What is the surface area??

1920 square inches

Step-by-step explanation:

First find the area of one triangle. The formula for finding the area of a triangle is A=(1/2)bh. The area of each triangle is the same since they are congruent. There are a total of 8 triangles so you would multiply the area of 1 triangle by the amount of triangle. 135*8=1080

next you need to find the area of the rectangles which are congruent. The area formula for a rectangle is A=lw so the area of one rectangle is 210 and there are 4 rectangle so 210*4=840. Next you add the total area of the triangles to the total area of the rectangles to get a solution of 1080+840=1920.

you have 6 equal triangles, find the area of one of them (b*h/2) and multiply by 6

(8*4: 2)*6 =

32 cm² is your answer