the inner circumference of a circular race track , 25 m wide , is 880 m . find radius of the outer circle ?
"let inner radius be r metres . then , 2 π r = 880 ⇔ r = ( 880 x ( 7 / 44 ) ) = 140 m . radius of outer circle = ( 140 + 25 ) m = 165 m . hence a"
add(25, divide(divide(880, const_pi), const_2))