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20210713 17:25:12
A circular cylinder is a figure whose bases are two parallel and congruent circles. In life, cylindrical objects include cow’s milk cans, cups, flowerpots, barrels, buckets…
Cylindrical volume is the amount of space the cylinder occupies.
Formula for the volume of a cylinder
To calculate the volume of a cylinder, multiply the height by the square of the radius of the circle’s base and the number pi. Inside:

You can review the formula for calculating the area around the cylinder and the total area of the cylinder.
Example of calculating the volume of a cylinder
Lesson 1:
Calculate the volume of a cylinder whose base radius is 7.1 cm; height equal to 5 cm.
Solution:
We have V=πr²h
the volume of the cylinder is: 3.14 x (7.1)² x 5 = 791.437 (cm³)
Lesson 2: A cylinder has a circumference of 20π cm² and a total area of 28π cm². Calculate the volume of that cylinder.
Solution:
The total area of the cylinder is Stp = Sxq + Sđ = 2πrh + 2πr²
So, 2πr² = 28π – 20π = 8π
Therefore, r = 2cm
The area around the cylinder is Sxq = 2πrh
20π = 2π.2.h
h = 5cm
The volume of the cylinder is V = r²h = .22.5 = 20π cm³
lesson 3: A cylinder has base circumference 20 cm, surrounding area 14 cm². Calculate the height of the cylinder and the volume of the cylinder.
Solution: The circumference of the base of the cylinder is the circumference of the circle = 2rπ = 20 cm
Surrounding area of cylinder: Sxq = 2πrh= 20 xh = 14
→ h = 14/20 = 0.7 (cm)
2rπ = 20 => r ~ 3.18 cm
Volume of cylinder: V = r² xh ~ 219.91 cm³
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#Formula #calculating #volume #cylinder #illustrated #exercises #bài