The base of a triangular pyramid is a triangle with corners at (3,8), (4,2), and (2,6). If the pyramid has a height of 7, what is the pyramid's volume?

1 Answer
Apr 9, 2016

volume =283

Explanation:

The volume of a pyramid is given by the formula:
XXXV=13hb where h is the height and b is the area of the base.

We are given the height (h=7)
so we need to find the base.

Method 1: Use the Pythagorean Theorem to find distance between points then apply Heron's Formula for the Area.
(left as an exercise).

Method 2: Evaluate the Area of the Triangular Base as the Sum and Difference of Trapezoids:
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From the relationship between the triangle and the trapezoid segments we see that the area of the base of our pyramid is
XXXb=7+58=4

Therefore the Volume of the pyramid is
XXXV=13×7×4=283