Answer: 56.52mm
Step-by-step explanation:
First, you have to find the circumference of the wheel and divide it by 25 since the spokes are equally spaced.
The equation for the circumference of a circle is:
C = 2πr
C = 2 x π x 225
C = 1413
Then, you divide it by 25
1413/25 = 56.52