The formula for the surface area of a square pyramid is:
SA = (side times side) + #offaces(1/2 b times slantheight)
If you put all of the numbers into place it would be:
SA = (10 times 10) + 4(1/2 10 times 15)
Then:
SA = 100 + 4(1/2 150)
SA = 100 + 4(75)
SA = 100 + 300
SA = 400
So, the surface area of this square pyramid is 400mm squared.
You're welcome.
