Answer:
468.4 meters
Step-by-step 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 pid, 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.
