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Find the measured of the numbered angles in the rectangle. Geometry Chapter 7.4

Find the measured of the numbered angles in the rectangle. Geometry Chapter 7.4-example-1

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Answer:

∠3 = 18°

∠4 = 144°

∠2 = 36°

∠1 = 72°

Explanation:

From the concept of alternate interior angles,

∠3 = 18°

Since the diagonal divides the rectangle into 4 parts with 2 of the rectangles being similar.

Then, the triangle with ∠3 & ∠4 is an Isosceles triangle and as such;

∠4 = 180 - 2(∠3)

∠4 = 180 - 2(18)

∠4 = 180 - 36

∠4 = 144°

∠2 = 180 - ∠4 (because sum of angles on a straight line is 180°)

∠2 = 180 - 144

∠2 = 36°

Like it was done for angle ∠4 above;

∠1 = (180 - 36)/2

∠1 = 144/2

∠1 = 72°

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