Respuesta :

I would find the missing angles of the the triangles, using the fact that "all triangles and lines are 180°"

40(angle on the left of B)+39(angle on the right of B)= 79
79 - 180 = 101

∠B is [C] 101°
The angle to the left of < B = 130 - 90 = 40 degrees

Angle to right of <B =  90-51 = 39 degrees

So m < B = 180 - 40 - 39  = 180 - 79 = 101 degrees
Q&A Education