Whats L.A when your trying to find surface area of a square-based pyramid?
LA stands for "lateral area."
Lateral area is the surface area except for the area of the base.
The lateral area of a pyramid = (1/2) * (perimeter of base) * (height)
Thanks guest
Could you please derive that formula ?
(My question is only intended for the guest who posted the formula)
I am sorry what I said is actually not good, I should have said slant height...
But here is my explanation. You can see how that it is because if you take the triangles and lay them out like this:
Since the base of each triangle is the same length,
area of one blue triange = (1/2)(1/4 * perimeter of base)(slant height)
There are 4 triangles total that area all the same size.. so,
area of all blue triangles = 4 * (1/2)(1/4 * perimeter of base)(slant height)
area of all blue triangles = (1/2)(perimeter of base)(slant height)