i have to solve for ABC n round to nearest whole number

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˚