Question

the base radius of a cylinder is 10.5cm and its height is 20cm.find the curved surface area and the volume of the cylinder.​

Answer 1

Answer:

• C.S.A.(curved surface area) = 1320cm²
• Volume = 6930cm³

Explanation:

Given, A cylinder with

• base radius = 10.5cm
• height = 20cm.

Curved surface area of the cylinder is given by,

$= \boldsymbol{2\pi rh}$

Where,

• $r$ denotes the base radius
• $h$ is the height.
• And taking $\pi$ as 22/7

Substitute the values,

$= 2 \times \dfrac{22}{7} \times 10.5 \times 20$

$= \dfrac{9240}{7}$

$\rm = 1320$

∴ Surface area of the cylinder is 1320cm²

Also, volume of the cylinder is given by,

$= \boldsymbol{\pi r {}^{2} h}$

$= \dfrac{22}{7} \times (10.5)^2 \times 20$

$= \dfrac{48510}{7}$

$= 6930$

∴ Volume of the cylinder is 6930cm³

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Answer 2

$\bold{Answer≈}$

Diameter of the base of the cone is 10.5 cm and slant height is 10 cm.

Curved surface area of a right circular cone of base radius, 'r' and slant height, 'l' is πrl.

Diameter of the base of a cone is 10.5 cm and its slant height is 10 cm. Find its curved surface area

Diameter, d = 10.5cm

Radius, r = 10.5/2 cm = 5.25 cm

Slant height, l = 10 cm

Curved surface area = πrl

= 22/7 × 5.25 × 10

= 165 cm²

Thus, curved surface area of the cone = 165 cm².