If the height of a cylinder of 10 cm is increased by 2 cm, its surface area will be increased by 125.6 square cm

If the height of a cylinder of 10 cm is increased by 2 cm, its surface area will be increased by 125.6 square cm

sixty-nine point zero eight

As shown in the figure: after a cylinder is cut off by 5 cm, the surface area of the cylinder is reduced by 31.4 square cm, so what is the original surface area of the cylinder
After a cylinder is cut off 5 cm, the surface area of the cylinder is reduced by 31.4 square cm. What is the original surface area of the cylinder?
What is the original height of the cylinder when the figure is not marked

Perimeter of bottom surface: 31.4 △ 5 = 6.28 (CM)
Bottom area: 3.14 × (6.28 △ 3.14 △ 2) ^ 2 = 3.14 (square centimeter)
Side area: 6.28 × 20 = 125.6 (cm2)
Surface area: 125.6 + 3.14 × 2 = 131.88 (cm2)

How many square centimeters is the surface area of a cylinder with a circumference of 28.26cm and a height of 10cm cut by + along the diameter of the bottom

28.26 △ 3.14 = 9 (CM)
After cutting by + along the bottom diameter, the surface area of the cylinder increases by two rectangles
9 × 10 × 2 = 180 (cm2)