Question

Find the area of a triangle with vertices at D(2, 0), E(–1, 0), and F(2, –7).

Answer 1

`(21)/(2)` units²

Explanation:

D and E lie on the x- axis and F is vertically below D

The triangle formed is right at D with legs of length 3 and 7

The area (A) of a right triangle is found using the formula

A =
`(1)/(2)` bh ( b is the base and h the perpendicular height )

here b = 3 and h = 7, hence

A =
`(1)/(2)` × 3 × 7 =
`(21)/(2)` units ²