Pi is commonly written as 3.14 even though it has an infinite decimal point value. 3pi multiplied by d (which d equaling 12pi) is our expression. Pi = 3.14. 3 x 3.14 = 9.42. 12 x 3.14 = 37.68. The expression is now 9.42 multiplied by 37.68. 9.42 x 37.68 = 353.8456.