Problem: the parameter of a square is equal to the perimeter of a rectangle of length 40 cm and breadth 20 cm . find the circumference of a semicircle whose diameter is equal to the side of the square . ( round off your answer to two decimal places ) ? 
Options: a ) 47.14 , b ) 45.15 , c ) 43.23 , d ) 41.44 , e ) 41.51
a