Question

QUICK YOU CAN GET 25 POINTS. Members of an art club paint a mural on a large wall that is shaped like a trapezoid. One base of the trapezoid is 20 feet long and the other base is half that length. A gallon of the paint they use covers 300 square feet. They use all but

1

5

of one gallon of the paint. What is the height of the wall? Complete the explanation.


The area of the trapezoid is

square feet. The lengths of the bases are 20 feet and

feet. The height of the trapezoid is

feet.

Answer 1

• area: 240 ft^2
• bases: 20 ft, 10 ft
• height: 16 ft

Explanation:

Apparently, 4/5 of a gallon is used, so covers ...

(4/5)(300 ft^2) = 240 ft^2

The area of the trapezoid is 240 square feet.

__

The short base of the trapezoid is half the length of the longer base, so is ...

(1/2)(20 ft) = 10 ft

The lengths of the bases are 20 ft and 10 ft.

__

The area formula for the trapezoid is ...

A = (1/2)(b1 +b2)h

Filling in the numbers we know, we can find h.

240 = (1/2)(20 +10)h

240 = 15h . . . . . simplify

16 = h . . . . . . . . . divide by 15

The height of the trapezoid is 16 feet.