Let’s solve each problem step by step. We’re working with right triangles, and we need to find sine, cosine, and tangent for the given angles.
Remember:
-
sin(angle) = opposite / hypotenuse
-
cos(angle) = adjacent / hypotenuse
-
tan(angle) = opposite / adjacent
Also: The hypotenuse is always the longest side — it’s across from the right angle.
We’ll go one triangle at a time.
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Problem 1: Triangle ABC (right angle at B)
Sides: AB = 9, BC = 12, AC = 15 → hypotenuse is AC = 15
Angle A:
- Opposite to A: BC = 12
- Adjacent to A: AB = 9
- Hypotenuse: AC = 15
→ sin(A) = 12/15 =
4/5
→ cos(A) = 9/15 =
3/5
→ tan(A) = 12/9 =
4/3
✔ Reduced fractions.
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Problem 2: Triangle DEF (right angle at D)
Sides: DF = 12, DE = 16, EF = 20 → hypotenuse is EF = 20
Angle F:
- Opposite to F: DE = 16
- Adjacent to F: DF = 12
- Hypotenuse: EF = 20
→ sin(F) = 16/20 =
4/5
→ cos(F) = 12/20 =
3/5
→ tan(F) = 16/12 =
4/3
✔ Reduced.
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Problem 3: Triangle QRS (right angle at R)
Sides: QR = 5, RS = 12, QS = 13 → hypotenuse is QS = 13
Angle Q:
- Opposite to Q: RS = 12
- Adjacent to Q: QR = 5
- Hypotenuse: QS = 13
→ sin(Q) = 12/13
→ cos(Q) = 5/13
→ tan(Q) = 12/5
✔ Already reduced.
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Problem 4: Triangle MNO (right angle at N)
Sides: MN = 24, NO = 10, MO = 26 → hypotenuse is MO = 26
Angle M:
- Opposite to M: NO = 10
- Adjacent to M: MN = 24
- Hypotenuse: MO = 26
→ sin(M) = 10/26 =
5/13
→ cos(M) = 24/26 =
12/13
→ tan(M) = 10/24 =
5/12
✔ Reduced.
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Problem 5: Triangle TUV (right angle at U)
Sides: TU = 3, UV = 4, TV = 5 → hypotenuse is TV = 5
First, angle V:
- Opposite to V: TU = 3
- Adjacent to V: UV = 4
- Hypotenuse: TV = 5
→ sin(V) = 3/5
→ cos(V) = 4/5
→ tan(V) = 3/4
Now angle T:
- Opposite to T: UV = 4
- Adjacent to T: TU = 3
- Hypotenuse: TV = 5
→ sin(T) = 4/5
→ cos(T) = 3/5
→ tan(T) = 4/3
✔ All reduced.
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Problem 6: Triangle GHI (right angle at H)
Sides: GH = 9, HI = 40, GI = 41 → hypotenuse is GI = 41
Angle G:
- Opposite to G: HI = 40
- Adjacent to G: GH = 9
- Hypotenuse: GI = 41
→ sin(G) = 40/41
→ cos(G) = 9/41
→ tan(G) = 40/9
Angle I:
- Opposite to I: GH = 9
- Adjacent to I: HI = 40
- Hypotenuse: GI = 41
→ sin(I) = 9/41
→ cos(I) = 40/41
→ tan(I) = 9/40
✔ All reduced.
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Problem 7: Triangle FGH (right angle at G)
Sides: FG = 8, GH = 15, FH = 17 → hypotenuse is FH = 17
Angle F:
- Opposite to F: GH = 15
- Adjacent to F: FG = 8
- Hypotenuse: FH = 17
→ sin(F) = 15/17
→ cos(F) = 8/17
→ tan(F) = 15/8
Angle H:
- Opposite to H: FG = 8
- Adjacent to H: GH = 15
- Hypotenuse: FH = 17
→ sin(H) = 8/17
→ cos(H) = 15/17
→ tan(H) = 8/15
✔ All reduced.
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Problem 8: Triangle RST (right angle at S)
Sides: RS = 12, ST = 35, RT = 37 → hypotenuse is RT = 37
Angle R:
- Opposite to R: ST = 35
- Adjacent to R: RS = 12
- Hypotenuse: RT = 37
→ sin(R) = 35/37
→ cos(R) = 12/37
→ tan(R) = 35/12
Angle T:
- Opposite to T: RS = 12
- Adjacent to T: ST = 35
- Hypotenuse: RT = 37
→ sin(T) = 12/37
→ cos(T) = 35/37
→ tan(T) = 12/35
✔ All reduced.
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Final Answer:
1.
sin(A) = 4/5
cos(A) = 3/5
tan(A) = 4/3
2.
sin(F) = 4/5
cos(F) = 3/5
tan(F) = 4/3
3.
sin(Q) = 12/13
cos(Q) = 5/13
tan(Q) = 12/5
4.
sin(M) = 5/13
cos(M) = 12/13
tan(M) = 5/12
5.
sin(V) = 3/5, sin(T) = 4/5
cos(V) = 4/5, cos(T) = 3/5
tan(V) = 3/4, tan(T) = 4/3
6.
sin(G) = 40/41, sin(I) = 9/41
cos(G) = 9/41, cos(I) = 40/41
tan(G) = 40/9, tan(I) = 9/40
7.
sin(F) = 15/17, sin(H) = 8/17
cos(F) = 8/17, cos(H) = 15/17
tan(F) = 15/8, tan(H) = 8/15
8.
sin(R) = 35/37, sin(T) = 12/37
cos(R) = 12/37, cos(T) = 35/37
tan(R) = 35/12, tan(T) = 12/35
Parent Tip: Review the logic above to help your child master the concept of geometry trig worksheet.