Question

The diagram shows a track composed with a semicircle on each end. The area of the rectangle is 8,400 square meters. What is the perimeter of the th rack? Use 3.14 for pi

Answer 1

468.4 meters

Explanation:

Find the width of the rectangle.

The area of a rectangle is A=length*width. Substitute the values of length and area and solve for width.

A=length*width

8,400=140*width

60= width

Use the width of the rectangle to find the circumference of the semicircles. Since each semicircle is half of a​ circle, the perimeter of the two semicircles is equal to the circumference of one circle.

The circumference of a circle is equal to pi​d, where d is the diameter. The diameter of the semicircle is the same as the width of the rectangle.

​So, the diameter is 60 meters. Substitute the diameter into the formula for the circumference and simplify using 3.14 for pi.

≈188.4

(2 times 140)+ 188.4

​So, the perimeter of the track is 468.4 meters.