Answer:
SA = 696cm^2
Explanation:
First we need to identify the shapes
There are 3 rectangles and 2 triangles
Now the individual surface area for each shape
20 x 10 = 200 (1 rectangle)
1/2(12 x 8) = 48 (1 triangle)
Now we add them together
(200 x 3) + (48 x 2) = 696