Question

What is the area of the triangle whose vertices are D( 3, 3), E(3, -1), and F(-2, -5)? Show ALL your work! Your choice of method on how to find the area.

Answer 1

Formula for the area of the triangle:

A = ( base x height ) / 2

For a base we can choose DE, because it is on the line x = 3.

So DE = 3 + | - 1 | = 3 + 1 = 4

And the height is the distance from the point F ( - 2 , - 5 ) to the line x = 3.

h = | - 2 | + 3 = 2 + 3 = 5

A (triangle DEF) = ( 4 x 5 ) / 2 = 20 / 2 = 10

Answer:

The area of the triangle DEF is 10.