Question

Johnny ran 20 laps around a circular field. If he covered a distance of 3265.6 metres, what is the radius of the circular field?

Answer 1

60?

Explanation:

2πr = 163.28

20(2πr) = 3265.6

r ≈ 60.927382

Answer 2

25.99 metres

Explanation:

2πr is the circumference equation for the distance of one lap. Multiply that by 20 to get the distance of the laps in total. Then, simplify with r (radius) as the variable to solve for.

20(2πr) = 3265.6

2πr = 163.28

r ≈ 25.986819108