The surface area is 216 cm sq.
Square base formula: length * width
One square base is 70 cm sq (7*10), another is 56 cm sq (7*8), and the final base is 42 cm sq (7*6).
The height of both triangular faces is 4.8 cm
The two triangular faces are 24 cm sq each, 48 cm sq when added together.
Add all 5 numbers up to get 216.
