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What is m∠A ?

Enter your answer in the box.

What is m∠A ? Enter your answer in the box.-example-1
User Mrug
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1 Answer

1 vote
First of all let's consider triangle CDE
∠C + ∠D + ∠CED = 180° [Angle sum property]
43 + 35 + ∠CED = 180°
78 + ∠CED = 180°
∠CED =180- 78 = 102°
∠CED = ∠BEA [Vertically opposite angels are equal]

In Triangle ABR
∠A + ∠B + ∠BEA = 180° [Angle sum property]
∠A + 18 + 102 = 180°
∠A + 120 = 180°
∠A = 180 - 120
∠A = 60°


Therefore, m∠A = 60°
User Kazuaki Suzuki
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8.3k points