Respuesta :

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 [tex]\frac{1}{2}bh[/tex]  where b is base and h is height.

base of triangle is 12 and height is 11

So area of each triangle is  [tex]\frac{1}{2}(12)(11)=66[/tex]

There are 4 of them, so total is 66 * 4 = 264

Now, square has an area of  [tex]s^2[/tex]  where s is the side length.

It is given s = 12, so the area of the square base is:

[tex](12)^2=144[/tex]

Total Surface Area of the Pyramid is  264 + 144 = 408 sq. in.