If the height of a cylinder is reduced by 1 cm, the surface area will be reduced by 18.84 square cm. What is the surface area of the cylinder

If the height of a cylinder is reduced by 1 cm, the surface area will be reduced by 18.84 square cm. What is the surface area of the cylinder

The perimeter of the bottom surface is: 18.84 △ 1 = 18.84 cm
The radius of the bottom surface is: 18.84 △ 2 △ 3.14 = 3cm
The area of the two bottoms is 3.14 × 3 × 3 × 2 = 56.52 square centimeter
Demand surface area, do not know high, how to seek?