BRAINLIESTPLEASE HELP

Step-by-step explanation:

In the question above we are given only diameter but our radius is not given. So to find radius, we have to divide our 45 by 2. Which is 45÷2 so our answer is 22.5 m.

a) question "a" is the same as finding the circumference of the circle.

So circumference= 2πr

C = 2 × 22/7 × 22.5

C = 44/7 × 22.5

Therefore our the distance round one lap = 141.42 meter.

b) now the "b" says he goes around the track 25 times per race. So we will therefore multiple the distance round one lap by the the number of times he races.

So 141.42 × 25 = 3535.5 meters

I hope this helps. Good luck

if a = 1,   and b = 2, then the answer is 47.99999999. if you round that to the nearest whole number, the answer is 48.