The angle measurements in the diagram are represented by the following expressions. \qquad \blueD{\angle A} = \blueD{5x -15 ^\circ}∠A=5x−15
∘
start color #11accd, angle, A, end color #11accd, equals, start color #11accd, 5, x, minus, 15, degrees, end color #11accd \qquad \green{\angle B} = \green{2x +21^\circ}∠B=2x+21
∘
start color #28ae7b, angle, B, end color #28ae7b, equals, start color #28ae7b, 2, x, plus, 21, degrees, end color #28ae7b

Solve for xxx and then find the measure of \greenD{\angle B}∠Bstart color #1fab54, angle, B, end color #1fab54: