jmc

Question

A triangle in a Cartesian coordinate plane has vertices (5, -2), (10, 5) and (5, 5). How many square units are in the area of the triangle? Express your answer as a decimal to the nearest tenth.

Accepted Answer

Plotting the given points in a coordinate plane, we find that the triangle is a right triangle whose legs have length

5 - (- 2) = 7

and

10 - 5 = 5

units. The area of the triangle is

\frac{1}{2} (base) (height) = \frac{1}{2} (7) (5) = 17.5

square units.