Question

Given the parallelogram ABCD, solve for X when angle A equals (30+ 5x)° and angle D equals (15+10x)° degrees. Also, sides AB and CD opposite each other.

Answer 1

x = 9

Explanation:

Adjacent angles A and D are supplementary:

(30 +5x)° +(15 +10x)° = 180°

15x +45 = 180 . . . . . collect terms, divide by °

15x = 135 . . . . . . . . . subtract 45

135/15 = x = 9 . . . . . divide by the coefficient of x

The value of x is 9.