Question

Point D (–2, 5)

Point E (1, 5)

Point F (–2, –3)

What is the area, in square units, of triangle DEF?

Answer 1

Note that DEF is a right triangle with legs meeting at D.  Find the area by multiplying the leg lengths together and dividing by 2.

The distance from D to F is 5-(-3)=8, and the distance from D to E is 1-(-2)=3.  Thus, the area of the triangle is 8*3/2=12.