Respuesta :

m<A + m<B + m<C = 180
48 + 6x - 28  + 2x = 180
8x + 20 = 180
8x = 160
x = 20

m<B = 6x - 28 = 6(20) - 28 = 120 -28 = 92
m<C = 2x = 2(20) = 40

answer
x =20
m<B = 92
m<C = 40