September 8, 2009
No CommentsHow to Find the Surface Area of a Cone
Description
This video gives a clear example on how to solve for the surface area of a cone. The formula is explained and a sample problem is solved in the video.
Overview
The surface area is the area of each side, or face, of the shape added together. Cones are a very tricky shape to calculate the surface area of, because there is something called a “slant height” that needs to be used. The formula for the surface area of a cone is:
SA = B + pi * r * l
B is the area of a base. The base of a cone is always a circle. r is the radius of the circle – the base. l is the slant height. Sometimes you are given the slant height, but not always. If the slant height is not given to you then you can use this formula to find it:
l = sqrt(r^2 + h^2)
h represents the regular height of the cone, as opposed to the slant height. This is actually the pythagorean theorem – you can form a right triangle with it if you draw a picture.
