Question 901357
The circumference of a circle plus two equal sides of a rectangle sum to 300 meters.


x = the diameter of each semicircle, and a capped side of the rectangle.
y = the uncapped side of the rectangle.


The radius of the equivalent circle is x/2; so the contribution to perimeter of each semicircle occurs TWICE, meaning the perimeter contribution is from a whole circle.  This distance is {{{2*pi*(x/2)=x*pi}}}.


The track perimeter includes the "circumference just discussed PLUS the uncapped rectangle lengths of y...


{{{highlight_green(2y+x*pi=300)}}}.


ALSO given, {{{highlight_green(xy=100pi)}}};


Two equations and two unknowns in x and y.