∠1 and angle, 2∠2 are supplementary angles. If m, angle, 1, equals, left bracket, 2, x, minus, 20, right bracket, degreesm∠1=(2x−20)
∘
and m, angle, 2, equals, left bracket, 3, x, plus, 15, right bracket, degreesm∠2=(3x+15)
∘
, then find the measure of angle, 2∠2.