A rectangular billet with a bottom area of 12.56 cm and a height of 8 cm is forged into a cylindrical part with a bottom radius of 3 cm. The length of the cylindrical part is calculated

A rectangular billet with a bottom area of 12.56 cm and a height of 8 cm is forged into a cylindrical part with a bottom radius of 3 cm. The length of the cylindrical part is calculated

12.56×8÷(3.14×3×3)
=100.48÷28.26
=3 and 5 / 9 cm