Question 828522
If {{{R}}}= radius of each circle, the rectangle's length and width should be {{{4R}}} and {{{2R}}} respectively.
{{{drawing(400,200,-22,22,-11,11,
rectangle(-20,-10,20,10),circle(10,0,0.2),
arrow(10,0,20,0),arrow(20,0,10,0),
locate(15,0,R),
circle(-10,0,10),circle(10,0,10))}}}
The perimeter of the rectangle is {{{2*(4R+2R)=2*6R=12R}}}
That is the distance A runs in one lap.
The circumference of a circle is {{{2pi*R}}} ,
and the distance that B runs in one lap is
{{{2*(2pi*R)=4pi*R}}} , which is longer than {{{12R}}} .
How much longer?
The difference is {{{4pi*R-12R}}} and as a fraction of {{{12R}}} it is
{{{(4pi*R-12R)/12R=(4pi-12)*R/12R=4pi/12/12=4pi/12-12/12=pi/3-1=about0.047}}}=4.7%
So B must run 4.7% more distance in the same time.
B must be 4.7% faster than A.