Jon,

First you need to decide which side of the triangle is the base, then the height is measured perpendicular to the base. The area can then be calculated using

area = 1/2 base × height.

So, for example, suppose I have a triangle with one side that measures 136 feet and its area is 10,230 square feet. If I make that side the base then

area = 1/2 base × height

so

10,230 = 1/2 × 136 × height = 68 × height

and hence

height = 10,230/68 = 150.44 feet.

Penny