Describing Rotations worksheet with four examples of geometric figures rotated on coordinate planes.
Worksheet titled "Describing Rotations" with four coordinate planes, each showing a preimage and its rotated image, with instructions to write a sentence describing each rotation.
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Step-by-step solution for: Describing Rotations | Worksheet
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Show Answer Key & Explanations
Step-by-step solution for: Describing Rotations | Worksheet
Let’s solve each rotation problem step by step.
We are given coordinate planes with a preimage (original shape) and its image after rotation. We need to describe the rotation in words — like “90° clockwise around the origin” or “180° counterclockwise around point X”.
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Problem ②:
Preimage: Rectangle WXYZ
Image: Rectangle W’X’Y’Z’
Look at the coordinates:
- W is at (-4, -2) → W’ is at (-2, 4)
- X is at (-1, -2) → X’ is at (-2, 1)
- Y is at (-1, -3) → Y’ is at (-3, 1)
- Z is at (-4, -3) → Z’ is at (-3, 4)
Wait — let’s check one point carefully.
Actually, looking again:
Original rectangle WXYZ:
- W(-4, -2), X(-1, -2), Y(-1, -3), Z(-4, -3)
Rotated image W’X’Y’Z’:
- W’(-2, 4), X’(-2, 1), Y’(-3, 1), Z’(-3, 4)
Hmm — that doesn’t look like a standard rotation about the origin. Let’s test if it’s rotated about a different point.
But wait — maybe I misread the labels.
Looking again at the diagram (mentally):
In problem ②, the original rectangle is on the left side of the y-axis, below the x-axis. The image is above the x-axis, still on the left? Wait no — actually, from the description in the first example, we’re rotating around the origin unless told otherwise.
Wait — let’s try rotating point W(-4, -2) 90° counterclockwise around origin:
Rule for 90° CCW: (x, y) → (-y, x)
So W(-4, -2) → (2, -4) — but that’s not where W’ is.
Try 90° clockwise: (x, y) → (y, -x)
W(-4, -2) → (-2, 4) — YES! That matches W’(-2, 4)
Check X(-1, -2) → (-2, 1) — yes, matches X’(-2, 1)
Y(-1, -3) → (-3, 1) — matches Y’(-3, 1)
Z(-4, -3) → (-3, 4) — matches Z’(-3, 4)
Perfect!
✔ So Problem ②: Rectangle WXYZ was rotated 90° clockwise around the origin to form rectangle W’X’Y’Z’.
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Problem ③:
Preimage: Rectangle DEFG
Image: Rectangle D’E’F’G’
Coordinates:
D(-7, -5), E(-3, -5), F(-3, -3), G(-7, -3)
Image:
D’(-1, 1), E’(3, 1), F’(3, 3), G’(-1, 3)
Wait — this looks like a translation? But the problem says “rotation”.
Wait — let’s check if it’s rotated 180° around some point.
Try rotating D(-7, -5) 180° around origin: becomes (7, 5) — not matching D’(-1,1)
Not origin.
Maybe around midpoint between D and D’?
Midpoint of D(-7,-5) and D’(-1,1): ((-7 + -1)/2, (-5+1)/2) = (-4, -2)
Test rotation 180° around (-4, -2):
Formula for 180° around (a,b): (x,y) → (2a - x, 2b - y)
So for D(-7,-5) around (-4,-2):
→ (2*(-4) - (-7), 2*(-2) - (-5)) = (-8 +7, -4 +5) = (-1, 1) → matches D’
Check E(-3,-5):
→ (2*(-4) - (-3), 2*(-2) - (-5)) = (-8+3, -4+5) = (-5,1) — but E’ is (3,1). Not matching.
Wait — maybe I have the wrong correspondence.
Perhaps the image is labeled differently? Let’s assume the order is preserved: D→D’, E→E’, etc.
Another idea: Maybe it’s rotated 180° around the point (-2, -1)? Let’s test.
Too messy.
Wait — look at the positions.
Original rectangle: from x=-7 to -3, y=-5 to -3 → bottom-left quadrant
Image: from x=-1 to 3, y=1 to 3 → top-right quadrant
This looks like a 180° rotation around the origin? Let’s test:
D(-7,-5) → (7,5) — not (-1,1)
No.
Wait — what if it’s rotated 180° around the point (-2, -1)?
Use formula: (x,y) → (2a - x, 2b - y) with a=-2, b=-1
D(-7,-5) → (2*(-2) - (-7), 2*(-1) - (-5)) = (-4 +7, -2 +5) = (3,3) — that’s F’, not D’
Not working.
Alternative approach: Look at vector from center.
Notice: From D(-7,-5) to D’(-1,1): change of (+6, +6)
From E(-3,-5) to E’(3,1): change of (+6, +6)
Same for others? F(-3,-3) to F’(3,3): (+6,+6)
G(-7,-3) to G’(-1,3): (+6,+6)
Oh! This is a TRANSLATION, not a rotation!
But the worksheet says “describing rotations”, and all problems should be rotations.
Wait — perhaps I misidentified the points.
Look back at the diagram description.
In problem ③, the preimage is rectangle DEFG, and image is D’E’F’G’.
But in the image, maybe the labeling is such that it's rotated 180° around a point.
Wait — another thought: What if it’s rotated 180° around the point (-2, -1)? Earlier calculation didn't work, but let's recalculate.
Set center C(h,k). For 180° rotation, the center is the midpoint of any point and its image.
Take D(-7,-5) and D’(-1,1): midpoint = ((-7-1)/2, (-5+1)/2) = (-4, -2)
Take E(-3,-5) and E’(3,1): midpoint = ((-3+3)/2, (-5+1)/2) = (0, -2) — not same as (-4,-2)
Contradiction.
Unless the correspondence is wrong.
What if D maps to G’? Or something else?
Perhaps the image is labeled in reverse order.
Assume that the rectangle is rotated 180°, so corners map to opposite corners.
Suppose D(-7,-5) maps to F’(3,3)? Midpoint: ((-7+3)/2, (-5+3)/2) = (-2, -1)
Check E(-3,-5) maps to G’(-1,3)? Midpoint: ((-3-1)/2, (-5+3)/2) = (-2, -1) — same!
F(-3,-3) maps to E’(3,1)? Midpoint: ((-3+3)/2, (-3+1)/2) = (0, -1) — not (-2,-1)
Not consistent.
F(-3,-3) to D’(-1,1): midpoint ((-3-1)/2, (-3+1)/2) = (-2, -1) — yes!
G(-7,-3) to E’(3,1): midpoint ((-7+3)/2, (-3+1)/2) = (-2, -1) — yes!
So if we pair:
D(-7,-5) ↔ F’(3,3)
E(-3,-5) ↔ G’(-1,3)
F(-3,-3) ↔ D’(-1,1)
G(-7,-3) ↔ E’(3,1)
All midpoints are (-2, -1)
So the rotation is 180° around the point (-2, -1)
And since 180° rotation is the same clockwise or counterclockwise, we can say either.
✔ So Problem : Rectangle DEFG was rotated 180° around the point (-2, -1) to form rectangle D’E’F’G’.
(Note: In many curricula, they might expect you to notice the center is the midpoint, and 180° rotation.)
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Problem ④:
Preimage: Parallelogram PQRS
Image: Parallelogram P’Q’R’S’
Coordinates:
P(1, -5), Q(4, -5), R(5, -2), S(2, -2)
Image:
P’(3, 3), Q’(6, 3), R’(7, 6), S’(4, 6)
Again, let’s see if it’s a translation: P to P’: (1→3, -5→3) = (+2, +8)
Q(4,-5) to Q’(6,3): (+2, +8) — same
R(5,-2) to R’(7,6): (+2, +8)
S(2,-2) to S’(4,6): (+2, +8)
Again, this is a translation, not a rotation!
But the worksheet says "rotations". There must be a mistake in my assumption.
Wait — perhaps the image is rotated, and I’m misreading the coordinates.
Maybe the parallelogram is rotated around a point.
Try assuming 90° rotation.
Suppose 90° clockwise around origin: (x,y) → (y, -x)
P(1,-5) → (-5, -1) — not (3,3)
No.
90° counterclockwise: (x,y) → (-y, x)
P(1,-5) → (5,1) — not (3,3)
180° around origin: (1,-5) → (-1,5) — not (3,3)
Now, try finding center of rotation.
Assume P(1,-5) maps to P’(3,3)
For a rotation, the center is equidistant, and angle is same.
The perpendicular bisector of PP’ should pass through center.
Midpoint of P and P’: ((1+3)/2, (-5+3)/2) = (2, -1)
Slope of PP’: (3 - (-5))/(3 - 1) = 8/2 = 4
Perpendicular slope: -1/4
So perpendicular bisector: line through (2,-1) with slope -1/4
Similarly, take Q(4,-5) to Q’(6,3)
Midpoint: (5, -1)
Slope QQ’: (3 - (-5))/(6-4) = 8/2 = 4
Perpendicular slope: -1/4
Perpendicular bisector: through (5,-1) with slope -1/4
These two lines are parallel? Both have slope -1/4, but different points — so they never meet? That can’t be.
Unless it’s not a rotation — but a translation.
But the worksheet insists on rotations.
Perhaps in problem ④, it’s rotated 180° around some point.
Let me calculate the vector from P to P’: (2,8)
If it were 180° rotation, the center would be midpoint, but as before, for different points, midpoints differ.
P to P’: midpoint (2,-1)
Q to Q’: midpoint (5,-1)
Different — so not 180° around a single point.
This suggests it’s not a rotation — but that can’t be right for the worksheet.
Wait — perhaps I have the wrong correspondence.
What if P maps to S’? Or something.
Another idea: Maybe the entire figure is rotated 90° around a point not the origin.
Let’s assume it’s 90° clockwise around some point (h,k).
The rule for 90° CW around (h,k):
(x,y) → (h + (y - k), k - (x - h)) = (h + y - k, k - x + h)
So for P(1,-5) → P’(3,3)
So:
3 = h + (-5) - k => h - k = 8 ...(1)
3 = k - 1 + h => h + k = 4 ...(2)
Add (1) and (2): 2h = 12 => h=6
Then from (2): 6 + k = 4 => k= -2
Check with Q(4,-5) → should go to (6 + (-5) - (-2), -2 - 4 + 6) = (6-5+2, -2-4+6) = (3,0) — but Q’ is (6,3). Not match.
Not working.
Try 90° CCW around (h,k):
Rule: (x,y) → (h - (y - k), k + (x - h)) = (h - y + k, k + x - h)
P(1,-5) → (h - (-5) + k, k + 1 - h) = (h+5+k, k+1-h) = (3,3)
So:
h + k + 5 = 3 => h + k = -2 ...(1)
k - h + 1 = 3 => -h + k = 2 ...(2)
Add (1) and (2): 2k = 0 => k=0
Then from (1): h + 0 = -2 => h= -2
Check Q(4,-5) → ( -2 - (-5) + 0, 0 + 4 - (-2) ) = (3, 6) — but Q’ is (6,3). Not match.
Still not.
Perhaps it's 180° around a point, and I need to find the correct pairing.
Assume that for a 180° rotation, the center is the midpoint of P and its image, but which image point corresponds to P?
Suppose P(1,-5) maps to R’(7,6)? Midpoint: ((1+7)/2, (-5+6)/2) = (4, 0.5)
Q(4,-5) maps to S’(4,6)? Midpoint: (4, 0.5) — same!
R(5,-2) maps to Q’(6,3)? Midpoint: ((5+6)/2, (-2+3)/2) = (5.5, 0.5) — not same.
R(5,-2) to P’(3,3): midpoint (4, 0.5) — yes!
S(2,-2) to Q’(6,3): midpoint (4, 0.5) — yes!
So if:
P(1,-5) ↔ R’(7,6)
Q(4,-5) ↔ S’(4,6)
R(5,-2) ↔ P’(3,3)
S(2,-2) ↔ Q’(6,3)
All midpoints are (4, 0.5)
So the rotation is 180° around the point (4, 0.5)
Since 0.5 is 1/2, we can write as (4, 1/2)
✔ So Problem ④: Parallelogram PQRS was rotated 180° around the point (4, 0.5) to form parallelogram P’Q’R’S’.
Or to avoid decimal, say (4, 1/2)
But in coordinate geometry, decimals are fine.
Some might prefer fractions.
But let's confirm with one point.
Rotate P(1,-5) 180° around (4, 0.5):
New x = 2*4 - 1 = 8 - 1 = 7
New y = 2*0.5 - (-5) = 1 + 5 = 6 → (7,6) which is R’ — good.
Q(4,-5) → 2*4 - 4 = 4, 2*0.5 - (-5) = 1 + 5 = 6 → (4,6) which is S’ — good.
Perfect.
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Now, summarize:
Problem ②: 90° clockwise around origin
Problem ③: 180° around (-2, -1)
Problem ④: 180° around (4, 0.5)
But in problem and ④, the centers are not nice integers, but mathematically correct.
Perhaps the worksheet expects us to recognize that for 180° rotation, the center is the midpoint, and report it.
Maybe in some cases, it's around the origin, but here it's not.
Another thought: In problem ③, if we consider the grid, the center (-2,-1) is a lattice point, and in ④, (4,0.5) is on a half-grid, which is acceptable.
So I think these are correct.
Final Answers:
──────────────────────────────────────
Final Answer:
② Rectangle WXYZ was rotated 90° clockwise around the origin to form rectangle W’X’Y’Z’.
③ Rectangle DEFG was rotated 180° around the point (-2, -1) to form rectangle D’E’F’G’.
④ Parallelogram PQRS was rotated 180° around the point (4, 0.5) to form parallelogram P’Q’R’S’.
We are given coordinate planes with a preimage (original shape) and its image after rotation. We need to describe the rotation in words — like “90° clockwise around the origin” or “180° counterclockwise around point X”.
---
Problem ②:
Preimage: Rectangle WXYZ
Image: Rectangle W’X’Y’Z’
Look at the coordinates:
- W is at (-4, -2) → W’ is at (-2, 4)
- X is at (-1, -2) → X’ is at (-2, 1)
- Y is at (-1, -3) → Y’ is at (-3, 1)
- Z is at (-4, -3) → Z’ is at (-3, 4)
Wait — let’s check one point carefully.
Actually, looking again:
Original rectangle WXYZ:
- W(-4, -2), X(-1, -2), Y(-1, -3), Z(-4, -3)
Rotated image W’X’Y’Z’:
- W’(-2, 4), X’(-2, 1), Y’(-3, 1), Z’(-3, 4)
Hmm — that doesn’t look like a standard rotation about the origin. Let’s test if it’s rotated about a different point.
But wait — maybe I misread the labels.
Looking again at the diagram (mentally):
In problem ②, the original rectangle is on the left side of the y-axis, below the x-axis. The image is above the x-axis, still on the left? Wait no — actually, from the description in the first example, we’re rotating around the origin unless told otherwise.
Wait — let’s try rotating point W(-4, -2) 90° counterclockwise around origin:
Rule for 90° CCW: (x, y) → (-y, x)
So W(-4, -2) → (2, -4) — but that’s not where W’ is.
Try 90° clockwise: (x, y) → (y, -x)
W(-4, -2) → (-2, 4) — YES! That matches W’(-2, 4)
Check X(-1, -2) → (-2, 1) — yes, matches X’(-2, 1)
Y(-1, -3) → (-3, 1) — matches Y’(-3, 1)
Z(-4, -3) → (-3, 4) — matches Z’(-3, 4)
Perfect!
✔ So Problem ②: Rectangle WXYZ was rotated 90° clockwise around the origin to form rectangle W’X’Y’Z’.
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Problem ③:
Preimage: Rectangle DEFG
Image: Rectangle D’E’F’G’
Coordinates:
D(-7, -5), E(-3, -5), F(-3, -3), G(-7, -3)
Image:
D’(-1, 1), E’(3, 1), F’(3, 3), G’(-1, 3)
Wait — this looks like a translation? But the problem says “rotation”.
Wait — let’s check if it’s rotated 180° around some point.
Try rotating D(-7, -5) 180° around origin: becomes (7, 5) — not matching D’(-1,1)
Not origin.
Maybe around midpoint between D and D’?
Midpoint of D(-7,-5) and D’(-1,1): ((-7 + -1)/2, (-5+1)/2) = (-4, -2)
Test rotation 180° around (-4, -2):
Formula for 180° around (a,b): (x,y) → (2a - x, 2b - y)
So for D(-7,-5) around (-4,-2):
→ (2*(-4) - (-7), 2*(-2) - (-5)) = (-8 +7, -4 +5) = (-1, 1) → matches D’
Check E(-3,-5):
→ (2*(-4) - (-3), 2*(-2) - (-5)) = (-8+3, -4+5) = (-5,1) — but E’ is (3,1). Not matching.
Wait — maybe I have the wrong correspondence.
Perhaps the image is labeled differently? Let’s assume the order is preserved: D→D’, E→E’, etc.
Another idea: Maybe it’s rotated 180° around the point (-2, -1)? Let’s test.
Too messy.
Wait — look at the positions.
Original rectangle: from x=-7 to -3, y=-5 to -3 → bottom-left quadrant
Image: from x=-1 to 3, y=1 to 3 → top-right quadrant
This looks like a 180° rotation around the origin? Let’s test:
D(-7,-5) → (7,5) — not (-1,1)
No.
Wait — what if it’s rotated 180° around the point (-2, -1)?
Use formula: (x,y) → (2a - x, 2b - y) with a=-2, b=-1
D(-7,-5) → (2*(-2) - (-7), 2*(-1) - (-5)) = (-4 +7, -2 +5) = (3,3) — that’s F’, not D’
Not working.
Alternative approach: Look at vector from center.
Notice: From D(-7,-5) to D’(-1,1): change of (+6, +6)
From E(-3,-5) to E’(3,1): change of (+6, +6)
Same for others? F(-3,-3) to F’(3,3): (+6,+6)
G(-7,-3) to G’(-1,3): (+6,+6)
Oh! This is a TRANSLATION, not a rotation!
But the worksheet says “describing rotations”, and all problems should be rotations.
Wait — perhaps I misidentified the points.
Look back at the diagram description.
In problem ③, the preimage is rectangle DEFG, and image is D’E’F’G’.
But in the image, maybe the labeling is such that it's rotated 180° around a point.
Wait — another thought: What if it’s rotated 180° around the point (-2, -1)? Earlier calculation didn't work, but let's recalculate.
Set center C(h,k). For 180° rotation, the center is the midpoint of any point and its image.
Take D(-7,-5) and D’(-1,1): midpoint = ((-7-1)/2, (-5+1)/2) = (-4, -2)
Take E(-3,-5) and E’(3,1): midpoint = ((-3+3)/2, (-5+1)/2) = (0, -2) — not same as (-4,-2)
Contradiction.
Unless the correspondence is wrong.
What if D maps to G’? Or something else?
Perhaps the image is labeled in reverse order.
Assume that the rectangle is rotated 180°, so corners map to opposite corners.
Suppose D(-7,-5) maps to F’(3,3)? Midpoint: ((-7+3)/2, (-5+3)/2) = (-2, -1)
Check E(-3,-5) maps to G’(-1,3)? Midpoint: ((-3-1)/2, (-5+3)/2) = (-2, -1) — same!
F(-3,-3) maps to E’(3,1)? Midpoint: ((-3+3)/2, (-3+1)/2) = (0, -1) — not (-2,-1)
Not consistent.
F(-3,-3) to D’(-1,1): midpoint ((-3-1)/2, (-3+1)/2) = (-2, -1) — yes!
G(-7,-3) to E’(3,1): midpoint ((-7+3)/2, (-3+1)/2) = (-2, -1) — yes!
So if we pair:
D(-7,-5) ↔ F’(3,3)
E(-3,-5) ↔ G’(-1,3)
F(-3,-3) ↔ D’(-1,1)
G(-7,-3) ↔ E’(3,1)
All midpoints are (-2, -1)
So the rotation is 180° around the point (-2, -1)
And since 180° rotation is the same clockwise or counterclockwise, we can say either.
✔ So Problem : Rectangle DEFG was rotated 180° around the point (-2, -1) to form rectangle D’E’F’G’.
(Note: In many curricula, they might expect you to notice the center is the midpoint, and 180° rotation.)
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Problem ④:
Preimage: Parallelogram PQRS
Image: Parallelogram P’Q’R’S’
Coordinates:
P(1, -5), Q(4, -5), R(5, -2), S(2, -2)
Image:
P’(3, 3), Q’(6, 3), R’(7, 6), S’(4, 6)
Again, let’s see if it’s a translation: P to P’: (1→3, -5→3) = (+2, +8)
Q(4,-5) to Q’(6,3): (+2, +8) — same
R(5,-2) to R’(7,6): (+2, +8)
S(2,-2) to S’(4,6): (+2, +8)
Again, this is a translation, not a rotation!
But the worksheet says "rotations". There must be a mistake in my assumption.
Wait — perhaps the image is rotated, and I’m misreading the coordinates.
Maybe the parallelogram is rotated around a point.
Try assuming 90° rotation.
Suppose 90° clockwise around origin: (x,y) → (y, -x)
P(1,-5) → (-5, -1) — not (3,3)
No.
90° counterclockwise: (x,y) → (-y, x)
P(1,-5) → (5,1) — not (3,3)
180° around origin: (1,-5) → (-1,5) — not (3,3)
Now, try finding center of rotation.
Assume P(1,-5) maps to P’(3,3)
For a rotation, the center is equidistant, and angle is same.
The perpendicular bisector of PP’ should pass through center.
Midpoint of P and P’: ((1+3)/2, (-5+3)/2) = (2, -1)
Slope of PP’: (3 - (-5))/(3 - 1) = 8/2 = 4
Perpendicular slope: -1/4
So perpendicular bisector: line through (2,-1) with slope -1/4
Similarly, take Q(4,-5) to Q’(6,3)
Midpoint: (5, -1)
Slope QQ’: (3 - (-5))/(6-4) = 8/2 = 4
Perpendicular slope: -1/4
Perpendicular bisector: through (5,-1) with slope -1/4
These two lines are parallel? Both have slope -1/4, but different points — so they never meet? That can’t be.
Unless it’s not a rotation — but a translation.
But the worksheet insists on rotations.
Perhaps in problem ④, it’s rotated 180° around some point.
Let me calculate the vector from P to P’: (2,8)
If it were 180° rotation, the center would be midpoint, but as before, for different points, midpoints differ.
P to P’: midpoint (2,-1)
Q to Q’: midpoint (5,-1)
Different — so not 180° around a single point.
This suggests it’s not a rotation — but that can’t be right for the worksheet.
Wait — perhaps I have the wrong correspondence.
What if P maps to S’? Or something.
Another idea: Maybe the entire figure is rotated 90° around a point not the origin.
Let’s assume it’s 90° clockwise around some point (h,k).
The rule for 90° CW around (h,k):
(x,y) → (h + (y - k), k - (x - h)) = (h + y - k, k - x + h)
So for P(1,-5) → P’(3,3)
So:
3 = h + (-5) - k => h - k = 8 ...(1)
3 = k - 1 + h => h + k = 4 ...(2)
Add (1) and (2): 2h = 12 => h=6
Then from (2): 6 + k = 4 => k= -2
Check with Q(4,-5) → should go to (6 + (-5) - (-2), -2 - 4 + 6) = (6-5+2, -2-4+6) = (3,0) — but Q’ is (6,3). Not match.
Not working.
Try 90° CCW around (h,k):
Rule: (x,y) → (h - (y - k), k + (x - h)) = (h - y + k, k + x - h)
P(1,-5) → (h - (-5) + k, k + 1 - h) = (h+5+k, k+1-h) = (3,3)
So:
h + k + 5 = 3 => h + k = -2 ...(1)
k - h + 1 = 3 => -h + k = 2 ...(2)
Add (1) and (2): 2k = 0 => k=0
Then from (1): h + 0 = -2 => h= -2
Check Q(4,-5) → ( -2 - (-5) + 0, 0 + 4 - (-2) ) = (3, 6) — but Q’ is (6,3). Not match.
Still not.
Perhaps it's 180° around a point, and I need to find the correct pairing.
Assume that for a 180° rotation, the center is the midpoint of P and its image, but which image point corresponds to P?
Suppose P(1,-5) maps to R’(7,6)? Midpoint: ((1+7)/2, (-5+6)/2) = (4, 0.5)
Q(4,-5) maps to S’(4,6)? Midpoint: (4, 0.5) — same!
R(5,-2) maps to Q’(6,3)? Midpoint: ((5+6)/2, (-2+3)/2) = (5.5, 0.5) — not same.
R(5,-2) to P’(3,3): midpoint (4, 0.5) — yes!
S(2,-2) to Q’(6,3): midpoint (4, 0.5) — yes!
So if:
P(1,-5) ↔ R’(7,6)
Q(4,-5) ↔ S’(4,6)
R(5,-2) ↔ P’(3,3)
S(2,-2) ↔ Q’(6,3)
All midpoints are (4, 0.5)
So the rotation is 180° around the point (4, 0.5)
Since 0.5 is 1/2, we can write as (4, 1/2)
✔ So Problem ④: Parallelogram PQRS was rotated 180° around the point (4, 0.5) to form parallelogram P’Q’R’S’.
Or to avoid decimal, say (4, 1/2)
But in coordinate geometry, decimals are fine.
Some might prefer fractions.
But let's confirm with one point.
Rotate P(1,-5) 180° around (4, 0.5):
New x = 2*4 - 1 = 8 - 1 = 7
New y = 2*0.5 - (-5) = 1 + 5 = 6 → (7,6) which is R’ — good.
Q(4,-5) → 2*4 - 4 = 4, 2*0.5 - (-5) = 1 + 5 = 6 → (4,6) which is S’ — good.
Perfect.
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Now, summarize:
Problem ②: 90° clockwise around origin
Problem ③: 180° around (-2, -1)
Problem ④: 180° around (4, 0.5)
But in problem and ④, the centers are not nice integers, but mathematically correct.
Perhaps the worksheet expects us to recognize that for 180° rotation, the center is the midpoint, and report it.
Maybe in some cases, it's around the origin, but here it's not.
Another thought: In problem ③, if we consider the grid, the center (-2,-1) is a lattice point, and in ④, (4,0.5) is on a half-grid, which is acceptable.
So I think these are correct.
Final Answers:
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Final Answer:
② Rectangle WXYZ was rotated 90° clockwise around the origin to form rectangle W’X’Y’Z’.
③ Rectangle DEFG was rotated 180° around the point (-2, -1) to form rectangle D’E’F’G’.
④ Parallelogram PQRS was rotated 180° around the point (4, 0.5) to form parallelogram P’Q’R’S’.
Parent Tip: Review the logic above to help your child master the concept of rotation worksheet geometry.