posted by Amey on .
It takes ten identical pices to form a circular track for a pair of toy racing cars. If the inside arc of each pair is 3.4 inches shorter than the outside arc, what is the width of the track?
any help would be greatly appreciated.
If you know that the circumference is C=2pi*r where r is the radius, then the total difference between the inside and outside radii is 10*3.4=34in. This means 2pi*r+34=2pi*R where r and R are the inner and outer radii respectively. Note that R-r is the track width.
Thus 34=2pi*R-2pi*r= 2pi(R-r) so
34/(2*pi) = R-r = track width