A cylinder is 8cm high and 25.12cm in circumference. Now it is cut vertically along its diameter and its surface area is increased______ Square centimeter

A cylinder is 8cm high and 25.12cm in circumference. Now it is cut vertically along its diameter and its surface area is increased______ Square centimeter

The diameter of the bottom surface: 25.12 △ 3.14 = 8 (CM), 8 × 8 × 2 = 128 (square cm). A: the surface area has increased by 128 square cm