A 10 cm high cylinder is sawed into two equal blocks along the diameter from the middle. The surface area is 80 square centimeters larger than the original. What is the diameter and volume of the cylinder

A 10 cm high cylinder is sawed into two equal blocks along the diameter from the middle. The surface area is 80 square centimeters larger than the original. What is the diameter and volume of the cylinder

Added two rectangular faces
So diameter = 80 △ 2 △ 10 = 4cm
Volume = 3.14 × (4 / 2) &# 178; × 10 = 125.6 cubic centimeter
If you understand and solve your problem,

If the height of a 10 cm cylinder increases by 2 cm, the surface area will increase by 125.6 square cm
Please write down what each step is and why!

1.  find the perimeter of the bottom surface: 125.6 △ 2 = 62.8 (CM)
2.  calculate the bottom radius: 62.8 △ 3.14 △ 2 = 10 (CM)
3. bottom area: 3.14 × 10 × 10 = 314 (square centimeter)
4. Calculate the original surface area of the cylinder: 62.8 × 10 + 314 × 2 = 1256 (square centimeter)

There is a cylinder with a height of 10 cm. After reducing its height by 2 cm, the surface area of the cylinder is reduced by 12.56 square cm. How many square cm is the volume of the original cylinder? （π=3.14）（　　）
A. 3.14B. 31.4C. 12.56D. 125.6

The radius of the bottom of the cylinder is: 12.56 △ 2 △ 3.14 △ 2 = 2 △ 2 = 1 (CM), 3.14 × 1 × 1 × 10 = 3.14 × 10 = 31.4 (cm3). Answer: the original volume of the cylinder is 31.4 cm3