Respuesta :

xenia168

Answer:

Step-by-step explanation:

( x )° + 60° + ( x - 20 )° = 180°

x + 60 + x - 20 = 180

2x + 40 = 180

2x = 140

x = 70

m ( ∠A ) = 70°

m ( ∠B ) = 50°

m ( ∠C ) = 60°