Answer:
504 cm squared
Explanation:
To find the surface area, find the area of the square base and add it to the area of each triangle face.
Find the area of the base by multiplying base length by base length.
Here the base is 12 x 12 = 144.
Find the area of each triangle face by multiplying 1/2 * b*h.
Here the area is 1/2 * 12 * 15 = 90. Since there are 4 faces, the total area is 4 * 90 = 360.
Together the surface area is 360 + 144 = 504.