Lot 21 is a trapezoid with the two bases

perpendicular to the road. The scale drawing

below uses the scale 1/2 inch = 40 feet.

Base 1=3.5 inches

Base 2=5 inches

height=4 inches

What is the approximate area of Lot 21?

(1 acre = 43,560 square feet)

A 1/2 acre

B 2 acres

C 2 1/2 acre

D 3 acres

Area of trapezoid is given by Area=1/2 (a+b) * h

but the scale is:

1/2in=40 ft

hence

1 in=80 ft

the dimensions of the trapezium is:

Base=80*3.5=280 ft

Base=80*5=400 ft

Height=80*4=320 ft

thus the area is:

A=1/2 (280+400) * 320

A=108,800

but

1 acre=43560 ft²

Thus:

108800 ft²=108800/435602.4977=~2.5 acres

Answer: C] 2.5 acres