Question

Can someone solve then explain the process of solving this?

Answer 1

Answer: angle A is none of those

Explanation:

the sum of all angles in a triangle = 180

one of the triangles is 90

we can form an equation:

90 + (x+69) + (x+39) = 180

90 + 2x + 108 = 180

198 + 2x = 180

2x = 180 - 198

2x = -18

x = - 9

angle A = x+39

substitute x = -9

angle A = -9 + 39 = 30

so angle A is none of those