so..hmm check the picture below
the pyramid is really just 4 triangles and 1 square at the bottom, all stacked up to each other at the edges
get the area of the square bottom, is just a 6x6 square, thus the name of the pyramid
and get the area of each triangle, notice the base is 6, the altitude or height is 9
and add them all up, that's the surface area of the pyramid
