To find the missing angle in each triangle, we use the rule that all three interior angles of a triangle add up to
180°.
We will solve each problem one by one:
1) Triangle TUV
* Given angles: $37^\circ$ and $63^\circ$.
* Add them: $37 + 63 = 100$.
* Subtract from 180: $180 - 100 = 80$.
* $m\angle U = 80^\circ$
2) Triangle ABC
* Given angles: $90^\circ$ (the square symbol means a right angle) and $46^\circ$.
* Add them: $90 + 46 = 136$.
* Subtract from 180: $180 - 136 = 44$.
* $m\angle B = 44^\circ$
3) Triangle PQR
* Given angles: $36^\circ$ and $51^\circ$.
* Add them: $36 + 51 = 87$.
* Subtract from 180: $180 - 87 = 93$.
* $m\angle Q = 93^\circ$
4) Triangle EFG
* Given angles: $47^\circ$ and $86^\circ$.
* Add them: $47 + 86 = 133$.
* Subtract from 180: $180 - 133 = 47$.
* $m\angle F = 47^\circ$
5) Triangle XYZ
* Given angles: $33^\circ$ and $118^\circ$.
* Add them: $33 + 118 = 151$.
* Subtract from 180: $180 - 151 = 29$.
* $m\angle Y = 29^\circ$
6) Triangle UVW
* Given angles: $42^\circ$ and $64^\circ$.
* Add them: $42 + 64 = 106$.
* Subtract from 180: $180 - 106 = 74$.
* $m\angle V = 74^\circ$
7) Triangle KLM
* Given angles: $60^\circ$ and $60^\circ$.
* Add them: $60 + 60 = 120$.
* Subtract from 180: $180 - 120 = 60$.
* $m\angle K = 60^\circ$
8) Triangle STU
* Given angles: $35^\circ$ and $35^\circ$.
* Add them: $35 + 35 = 70$.
* Subtract from 180: $180 - 70 = 110$.
* $m\angle U = 110^\circ$
9) Triangle CDE
* Given angles: $53^\circ$ and $77^\circ$.
* Add them: $53 + 77 = 130$.
* Subtract from 180: $180 - 130 = 50$.
* To find the missing angle in each triangle, we use the rule that
all three interior angles of a triangle add up to 180°.
We will solve each problem one by one:
---
1) Triangle TUV:
Given: T = 37°, ∠V = 63°
Find: ∠U
→ 37 + 63 = 100
→ 180 - 100 =
80°
---
2) Triangle ABC (right triangle at C):
Given: ∠C = 90°, ∠A = 46°
Find: ∠B
→ 90 + 46 = 136
→ 180 - 136 =
44°
---
3) Triangle PQR:
Given: ∠P = 51°, ∠R = 36°
Find: ∠Q
→ 51 + 36 = 87
→ 180 - 87 =
93°
---
4) Triangle EFG:
Given: ∠E = 47°, ∠G = 86°
Find: ∠F
→ 47 + 86 = 133
→ 180 - 133 =
47°
---
5) Triangle XYZ:
Given: ∠X = 33°, ∠Z = 118°
Find: ∠Y
→ 33 + 118 = 151
→ 180 - 151 =
29°
---
6) Triangle UVW:
Given: ∠U = 64°, ∠W = 42°
Find: ∠V
→ 64 + 42 = 106
→ 180 - 106 =
74°
---
7) Triangle KLM:
Given: ∠L = 60°, ∠M = 60°
Find: ∠K
→ 60 + 60 = 120
→ 180 - 120 =
60°
*(This is an equilateral triangle — all angles are 60°)*
---
8) Triangle STU:
Given: ∠S = 35°, ∠T = 35°
Find: ∠U
→ 35 + 35 = 70
→ 180 - 70 =
110°
---
9) Triangle CDE:
Given: D = 77°, ∠E = 53°
Find: ∠C
→ 77 + 53 = 130
→ 180 - 130 =
50°
---
Final Answer:
1) m∠U = 80°
2) m∠B = 44°
3) m∠Q = 93°
4) m∠F = 47°
5) m∠Y = 29°
6) m∠V = 74°
7) m∠K = 60°
8) m∠U = 110°
9) m∠C = 50°
Parent Tip: Review the logic above to help your child master the concept of missing angles in a triangle worksheet.
