Angles in parallel lines worksheet with diagrams and questions.
Worksheet titled "Angles: Parallel Lines" from Corbettmaths, featuring multiple diagrams with parallel lines and transversals, asking to find angle x in each question with reasons.
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Step-by-step solution for: SOLUTION: Red and amber angles in parallel lines worksheet - Studypool
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Show Answer Key & Explanations
Step-by-step solution for: SOLUTION: Red and amber angles in parallel lines worksheet - Studypool
Let's solve Question 3 from the worksheet: Find the angle $ x $ in each diagram, using properties of parallel lines and angles.
We'll go through each part step by step. The key angle rules we'll use are:
- Corresponding angles are equal (when two parallel lines are cut by a transversal).
- Alternate angles are equal.
- Co-interior (or consecutive) angles add up to $ 180^\circ $.
- Vertically opposite angles are equal.
- Angles on a straight line sum to $ 180^\circ $.
---
Given:
- Line BD ∥ EG
- Angle at F is $ 125^\circ $
- We need to find angle $ x $ at point C.
Looking at the diagram:
- The $ 125^\circ $ angle is on line EG, between EF and HF.
- Since BD ∥ EG and AH is a transversal, the angle $ x $ at point C is corresponding to the angle adjacent to $ 125^\circ $ on the same side.
But wait — $ 125^\circ $ and its adjacent angle on the straight line make $ 180^\circ $. So the adjacent angle at F is:
$$
180^\circ - 125^\circ = 55^\circ
$$
This $ 55^\circ $ angle is corresponding to angle $ x $ at point C (since both are on the same side of the transversal and between the parallel lines).
So:
$$
x = 55^\circ \quad \text{(Corresponding angles)}
$$
✔ Answer: $ x = 55^\circ $
---
Given:
- BD ∥ EG
- Angle at C is $ 57^\circ $
- Need to find $ x $ at F
The $ 57^\circ $ angle is at point C on line BD. It’s formed between BC and AC.
Since BD ∥ EG and AH is the transversal, the angle $ x $ at F is alternate to the $ 57^\circ $ angle.
Alternate angles are equal when lines are parallel.
So:
$$
x = 57^\circ \quad \text{(Alternate angles)}
$$
✔ Answer: $ x = 57^\circ $
---
Given:
- BD ∥ EG
- Angle at H is $ 70^\circ $
- Need to find $ x $ at F
The $ 70^\circ $ angle is at point H, below EG. It's between EH and FH.
Now, look at the angle at F — it's above EG, and on the same side as the $ 70^\circ $ angle.
But this is co-interior (same-side interior) angle with $ 70^\circ $. Co-interior angles add up to $ 180^\circ $ when lines are parallel.
So:
$$
x + 70^\circ = 180^\circ \\
x = 180^\circ - 70^\circ = 110^\circ
$$
✔ Answer: $ x = 110^\circ $
*(Reason: Co-interior angles add to $ 180^\circ $)*
---
Given:
- BD ∥ EG
- Angle at C is $ 105^\circ $
- Need to find $ x $ at F
The $ 105^\circ $ angle is at C, on line BD. It's between BC and AC.
Now, $ x $ is at F, on line EG, and is on the same side of the transversal.
But note: This $ 105^\circ $ angle is not adjacent to the transversal in the same way. Let's check what kind of angle $ x $ is.
Actually, $ x $ is alternate to the angle that is vertically opposite to $ 105^\circ $.
Wait — better: The $ 105^\circ $ angle is on the upper line, and $ x $ is on the lower line, but on the opposite side of the transversal? No — let’s clarify.
Actually, $ x $ is corresponding to the angle adjacent to $ 105^\circ $?
No — simpler: The $ 105^\circ $ angle and $ x $ are co-interior angles? Wait.
Wait: $ 105^\circ $ is on the top line, and $ x $ is on the bottom line, and they are on the same side of the transversal → so they are co-interior angles.
So:
$$
x + 105^\circ = 180^\circ \Rightarrow x = 75^\circ
$$
✔ Answer: $ x = 75^\circ $
*(Reason: Co-interior angles add to $ 180^\circ $)*
---
Given:
- BD ∥ EG
- Angle at C is $ 53^\circ $
- Need to find $ x $ at F
The $ 53^\circ $ angle is at C, between BC and AC.
Now, $ x $ is at F, on line EG, and appears to be below the transversal.
But $ x $ is vertically opposite to the angle at F that corresponds to $ 53^\circ $? Let’s think.
Actually, $ 53^\circ $ and $ x $ are alternate interior angles.
Yes! Because:
- The transversal cuts the two parallel lines.
- $ 53^\circ $ is inside the parallel lines, on one side.
- $ x $ is inside, on the other side, but same relative position.
So $ x $ is alternate to $ 53^\circ $ → they are equal.
✔ Answer: $ x = 53^\circ $
*(Reason: Alternate angles are equal)*
---
Given:
- BD ∥ EG
- Angle at F is $ 133^\circ $
- Need to find $ x $ at C
$ 133^\circ $ is at F, on line EG, between EF and HF.
This is co-interior with the angle at C on the top line.
So:
$$
x + 133^\circ = 180^\circ \Rightarrow x = 47^\circ
$$
✔ Answer: $ x = 47^\circ $
*(Reason: Co-interior angles add to $ 180^\circ $)*
---
## ✔ Summary for Question 3:
| Part | Answer | Reason |
|------|--------|--------|
| (a) | $ x = 55^\circ $ | Corresponding angles; $ 180^\circ - 125^\circ = 55^\circ $ |
| (b) | $ x = 57^\circ $ | Alternate angles |
| (c) | $ x = 110^\circ $ | Co-interior angles: $ 180^\circ - 70^\circ $ |
| (d) | $ x = 75^\circ $ | Co-interior angles: $ 180^\circ - 105^\circ $ |
| (e) | $ x = 53^\circ $ | Alternate angles |
| (f) | $ x = 47^\circ $ | Co-interior angles: $ 180^\circ - 133^\circ $ |
---
Now, moving to Question 4 — however, the diagrams are blurry or not clearly visible. But I can still help if you describe them or provide clearer images.
Would you like me to attempt Question 4 based on your description or try to interpret the diagrams?
We'll go through each part step by step. The key angle rules we'll use are:
- Corresponding angles are equal (when two parallel lines are cut by a transversal).
- Alternate angles are equal.
- Co-interior (or consecutive) angles add up to $ 180^\circ $.
- Vertically opposite angles are equal.
- Angles on a straight line sum to $ 180^\circ $.
---
(a)
Given:
- Line BD ∥ EG
- Angle at F is $ 125^\circ $
- We need to find angle $ x $ at point C.
Looking at the diagram:
- The $ 125^\circ $ angle is on line EG, between EF and HF.
- Since BD ∥ EG and AH is a transversal, the angle $ x $ at point C is corresponding to the angle adjacent to $ 125^\circ $ on the same side.
But wait — $ 125^\circ $ and its adjacent angle on the straight line make $ 180^\circ $. So the adjacent angle at F is:
$$
180^\circ - 125^\circ = 55^\circ
$$
This $ 55^\circ $ angle is corresponding to angle $ x $ at point C (since both are on the same side of the transversal and between the parallel lines).
So:
$$
x = 55^\circ \quad \text{(Corresponding angles)}
$$
✔ Answer: $ x = 55^\circ $
---
(b)
Given:
- BD ∥ EG
- Angle at C is $ 57^\circ $
- Need to find $ x $ at F
The $ 57^\circ $ angle is at point C on line BD. It’s formed between BC and AC.
Since BD ∥ EG and AH is the transversal, the angle $ x $ at F is alternate to the $ 57^\circ $ angle.
Alternate angles are equal when lines are parallel.
So:
$$
x = 57^\circ \quad \text{(Alternate angles)}
$$
✔ Answer: $ x = 57^\circ $
---
(c)
Given:
- BD ∥ EG
- Angle at H is $ 70^\circ $
- Need to find $ x $ at F
The $ 70^\circ $ angle is at point H, below EG. It's between EH and FH.
Now, look at the angle at F — it's above EG, and on the same side as the $ 70^\circ $ angle.
But this is co-interior (same-side interior) angle with $ 70^\circ $. Co-interior angles add up to $ 180^\circ $ when lines are parallel.
So:
$$
x + 70^\circ = 180^\circ \\
x = 180^\circ - 70^\circ = 110^\circ
$$
✔ Answer: $ x = 110^\circ $
*(Reason: Co-interior angles add to $ 180^\circ $)*
---
(d)
Given:
- BD ∥ EG
- Angle at C is $ 105^\circ $
- Need to find $ x $ at F
The $ 105^\circ $ angle is at C, on line BD. It's between BC and AC.
Now, $ x $ is at F, on line EG, and is on the same side of the transversal.
But note: This $ 105^\circ $ angle is not adjacent to the transversal in the same way. Let's check what kind of angle $ x $ is.
Actually, $ x $ is alternate to the angle that is vertically opposite to $ 105^\circ $.
Wait — better: The $ 105^\circ $ angle is on the upper line, and $ x $ is on the lower line, but on the opposite side of the transversal? No — let’s clarify.
Actually, $ x $ is corresponding to the angle adjacent to $ 105^\circ $?
No — simpler: The $ 105^\circ $ angle and $ x $ are co-interior angles? Wait.
Wait: $ 105^\circ $ is on the top line, and $ x $ is on the bottom line, and they are on the same side of the transversal → so they are co-interior angles.
So:
$$
x + 105^\circ = 180^\circ \Rightarrow x = 75^\circ
$$
✔ Answer: $ x = 75^\circ $
*(Reason: Co-interior angles add to $ 180^\circ $)*
---
(e)
Given:
- BD ∥ EG
- Angle at C is $ 53^\circ $
- Need to find $ x $ at F
The $ 53^\circ $ angle is at C, between BC and AC.
Now, $ x $ is at F, on line EG, and appears to be below the transversal.
But $ x $ is vertically opposite to the angle at F that corresponds to $ 53^\circ $? Let’s think.
Actually, $ 53^\circ $ and $ x $ are alternate interior angles.
Yes! Because:
- The transversal cuts the two parallel lines.
- $ 53^\circ $ is inside the parallel lines, on one side.
- $ x $ is inside, on the other side, but same relative position.
So $ x $ is alternate to $ 53^\circ $ → they are equal.
✔ Answer: $ x = 53^\circ $
*(Reason: Alternate angles are equal)*
---
(f)
Given:
- BD ∥ EG
- Angle at F is $ 133^\circ $
- Need to find $ x $ at C
$ 133^\circ $ is at F, on line EG, between EF and HF.
This is co-interior with the angle at C on the top line.
So:
$$
x + 133^\circ = 180^\circ \Rightarrow x = 47^\circ
$$
✔ Answer: $ x = 47^\circ $
*(Reason: Co-interior angles add to $ 180^\circ $)*
---
## ✔ Summary for Question 3:
| Part | Answer | Reason |
|------|--------|--------|
| (a) | $ x = 55^\circ $ | Corresponding angles; $ 180^\circ - 125^\circ = 55^\circ $ |
| (b) | $ x = 57^\circ $ | Alternate angles |
| (c) | $ x = 110^\circ $ | Co-interior angles: $ 180^\circ - 70^\circ $ |
| (d) | $ x = 75^\circ $ | Co-interior angles: $ 180^\circ - 105^\circ $ |
| (e) | $ x = 53^\circ $ | Alternate angles |
| (f) | $ x = 47^\circ $ | Co-interior angles: $ 180^\circ - 133^\circ $ |
---
Now, moving to Question 4 — however, the diagrams are blurry or not clearly visible. But I can still help if you describe them or provide clearer images.
Would you like me to attempt Question 4 based on your description or try to interpret the diagrams?
Parent Tip: Review the logic above to help your child master the concept of angles and parallel lines worksheet answers.