Let’s solve each angle step by step. We’ll use two key facts:
-
Right angles = 90° → If two angles make a right angle, they add to 90°.
-
Straight lines = 180° → Angles on a straight line add up to 180°.
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Section A: Right Angles (add to 90°)
1.
a° + 25° = 90°
→ a° = 90 - 25 =
65°
2.
b° + 15° = 90°
→ b° = 90 - 15 =
75°
3.
c° + 80° = 90°
→ c° = 90 - 80 =
10°
4.
d° + 72° = 90°
→ d° = 90 - 72 =
18°
5.
e° + 34° = 90°
→ e° = 90 - 34 =
56°
6.
f° + 79° = 90°
→ f° = 90 - 79 =
11°
✔ All Section A done.
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Section B: Straight Lines (add to 180°)
7.
g° + 45° = 180°
→ g° = 180 - 45 =
135°
8.
h° + 128° = 180°
→ h° = 180 - 128 =
52°
9.
i° + 104° = 180°
→ i° = 180 - 104 =
76°
10.
j° + 71° + 48° = 180°
→ j° = 180 - 71 - 48 = 180 - 119 =
61°
11.
k° + 90° + 11° = 180° (right angle is 90°)
→ k° = 180 - 90 - 11 = 90 - 11 =
79°
12.
l° + 43° = 180°
→ l° = 180 - 43 =
137°
13.
m° + 25° + 78° = 180°
→ m° = 180 - 25 - 78 = 180 - 103 =
77°
14.
n° + 90° + 16° = 180° (right angle shown)
→ n° = 180 - 90 - 16 = 90 - 16 =
74°
15.
p° + 90° + 66° = 180° (right angle shown)
→ p° = 180 - 90 - 66 = 90 - 66 =
24°
16.
q° + q° + q° = 180° → three equal angles on a straight line
→ 3 × q° = 180°
→ q° = 180 ÷ 3 =
60°
✔ All Section B done.
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Final Answer:
a° = 65
b° = 75
c° = 10
d° = 18
e° = 56
f° = 11
g° = 135
h° = 52
i° = 76
j° = 61
k° = 79
l° = 137
m° = 77
n° = 74
p° = 24
q° = 60
Parent Tip: Review the logic above to help your child master the concept of missing angle worksheet.
