Answer:
360 cm^2.
Step-by-step explanation:
Area of the base = 10*10 = 100 cm^2.
We find the slant height of the sides using Pythagoras:
h = sqrt ( 12^2 + 5^2)
h = sqrt 169
h = 13.
Area of the triangular sides = 4 * 1/2 * 10* 13
= 260 cm^2
So the total surface area = 100 + 260
= 360 cm^2.