Answer:
408 sq. in.
Step-by-step explanation:
The total surface area of the pyramid is the sum of all 4 faces (each of them a triangle) and square base.
Triangle area is where b is base and h is height.
base of triangle is 12 and height is 11
So area of each triangle is
There are 4 of them, so total is 66 * 4 = 264
Now, square has an area of where s is the side length.
It is given s = 12, so the area of the square base is:
Total Surface Area of the Pyramid is 264 + 144 = 408 sq. in.