Expert: Steve Holleran - 5/15/2007

Question
What is the formula for a parallelogram, a triangle, and the suface area of a prism?  

Answer
Hello Haley,

Well, I'm not sure what formulas you are looking for when you ask about the parallelogram and triangle.  Do you want area formulas?

If so, the parallelogram area formula is

               Area = B * H    where B is the base and H is the perpendicular height (NOT the slant height).

For the triangle, the formula is

                Area = 1/2 * B * H,   where again the B is the base and H is the perpendicular height to that base.

For a prism, you can basically think to find the area of each face and just add them all up.  There is also a formula which does just that, and it goes

    Surface Area = 2 * Area of Base +
                              Perimeter of Base * Height


I hope this is what you were asking about.

Steve Holleran