First, we will find the area of one of the triangles. The area of a triangle is equal to 1/2*b*h. The base is 7 and the height is 9. 1/2*7*9=31.5. There are 4 triangles so we will multiply 31.5 by 4. 31.5*4=126.
Then we need to find the area of the base of the pyramid. The area is equal to w*l. The width and length are both 7. 7*7=49.
We will add the area of the base and the area of the 4 triangles together to come up with the surface area. 126+49=175.
The Surface area of the pyramid is 175 cm^2.
