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A mathematical problem: after a 16 cm long cylinder is cut off by 6 cm, the surface area of the cylinder is reduced by 37.68 square cm. What is the original surface area of the cylinder?
Circumference of circle: 37.68 △ 6 = 6.28 (CM)
Radius of circle: 6.28 △ 3.14 △ 2 = 1 (CM)
The sum of the area of the top and bottom of the cylinder: 3.14 × 1 & sup2; × 2 = 6.28 (square centimeter)
Side area of cylinder: 6.28 × 16 = 100.48 (cm2)
Surface area of original cylinder: 100.48 + 6.28 = 106.76 (cm2)
Calculate the surface area of the cylinder below
1. Diameter 12 cm,
2. 5 cm in diameter,
3. Diameter 18 cm,
1. Side area 12 × 3.14 × 16 = 602.88 square centimeter
Bottom area = 3.14 × (12 / 2) &# 178; = 113.04 square centimeter
Surface area = 602.88 + 113.04 × 2 = 828.96 square centimeter
2. Side area 3.14 × 5 × 20 = 314 square cm
Bottom area = 3.14 × (5 / 2) &# 178; = 19.625 square centimeter
Surface area = 19.625 × 2 + 314 = 353.25 square centimeter
3. Side area 3.14 × 18 × 15 = 847.8 square centimeter
Bottom area = 3.14 × (18 / 2) &# 178; = 254.34 square centimeter
Surface area = 254.34 × 2 + 847.8 = 1356.48 square centimeter
Calculate the surface area of each cylinder below
Come on, come on, come on~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
It's a process
Figure 1: 3.14 × (12 / 2) × (12 / 2) × 2 + 3.14 × 12 × 16
=226.08+602.88
=828.96 (cm2)
Figure 2: 3.14 × (5 / 2) × (5 / 2) × 2 + 3.14 × 5 × 20
=39.25+314
=353.25 (cm2)
Figure 3: 3.14 × (18 / 2) × (18 / 2) × 2 + 3.14 × 18 × 15
=508.68+647.8
=1356.48 (cm2)
Here is an expanded view of the side of a cylinder. Calculate the surface area and volume of the cylinder
Detailed formula! There are three data, height is 20cm, bottom is 25.12cm, hypotenuse is 25cm
Height 20cm, bottom 25.12cm, hypotenuse 25cm
The radius is: 25.12 △ 3.14 △ 2 = 4 (CM)
Bottom area: 4x4x3.14x2 = 100.48 (cm2)
Surface area: 25.12x20 = 502.4 (cm2) 502.4 + 100.48 = 602.88 (cm2)
Volume: 100.48x20 = 2009.6 (cm3)
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