Respuesta :

Answer:

C. 189

Step-by-step explanation:

Each triangle is 27 which makes it 108, and 108+81=189

Surface area = sum of all area, which is the total of 4 triangles and 1 square.

1 square = 9 x9 = 81

each triangle = (6 x 9)/2 = 27

so 4 triangles = 27 x 4 = 108

=> total = 108+ 81 = 189