Question

In parallelogram ABCD, ∠Aand ∠Bare adjacent. The measure of ∠Bis two times the measure of ∠A Which equation gives the exact measure of ∠A

Answer 1

Let x be the measure of ∠A, so the measure of ∠B = 2x.

The equation is :

x + 2x = 180° ⇒ 3x = 180° ⇒ x = 180°:3 ⇒ x = 60°

So, m(∡A) = 60°.

Answer 2

According to the properties of parallelograms, two adjacent angles (A and B) are supplementary, i.e. they add up to 180 ° .

This means that
B+A=180, or using B=2A =>
2A+A=180
=>
3A=180