Question

One angle of a quadrilateral is 60° and the remaining three interior angles are equal. Find the measure of each of the remaining angles.​

Answer 1

Here’s your answer:

Given one angle is 60° and the remaining 3 interior angles are equal.

Let ∠D = 60° and ∠A = ∠B = ∠C be x

We know that the sum of interior angles of quadrilateral is 360°

So ∠A + ∠B + ∠C + ∠D = 360°

x + x + x + 60° = 360°

3x + 60° = 360°

3x = 360° - 60°

3x = 300°

x = 300°/3

x = 100°

Therefore ∠A = ∠B = ∠C = 100°

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