what is the area of a pentagon...?

This is a tedious but straight forward problem. Draw the pentagon and locate the center point. From that point draw five lines to each of the corners. You now have 5 equal and congruent isosceles triangles. Find the area of one and multiply by 5. You already know the base but don't know the altitude. You figure that out by drawing a line from the center point to the midpoint of the base of one of the triangles. This line bisects the angle and is perpendicular to the base and creates 2 right triangles that are mirror images of one another. Solve the right triangles for their various angles which should be 36, 54 and 90 deg. Now apply the law of sines to obtain the length of the altitude that you are seeking. You now have all the info to calculate the area you want. Easy isn't it?

well a pentagon is made up of 3 triangles i believe

if the area of a triangle is bh/2. u know the base of the triangles in the pentagon is 64 and the height is 64. once u find the area of one of the 3 triangles, multiply it by three and there.