Respuesta :

Answer:

∠B

7(13)-1=90˚

Step-by-step explanation:

Are you saying ∠ABC or ABC as sides?

1. ∠ABC

(7x-1)+(4x+1)+(3x-2)=180˚

14x-2=180˚

14x=182

x=182/14

x=13˚

2. plug in

∠A

4(13)+1=53˚

∠B

7(13)-1=90˚

∠C

3(13)-2=37˚