Question

The circumference of the base of a right circular cone is 22cm and its slant height is 8cm. Its curved surface area is: i. 100cm2 ii. 90cm2 iii. 88cm2 iv. 77cm2​

Answer 1

Answer:

The volume of the cone is 102.66 cm³.

Step-by-step explanation:

Given : The circumference of the base of a right circular cone is 22 cm. If the height be 8 cm.

To find : The volume of cone ?

Solution :

Circumference of the base of cylinder is

C=2\pi rC=2πr

22=2\times \frac{22}{7}\times r22=2×722×r

r=\frac{22\times 7}{2\times 22}r=2×2222×7

r=3.5r=3.5

The radius is 3.5 cm.

Volume of a cylinder is given by,

V=\frac{1}{3}\pi r^2hV=31πr2h

V=\frac{1}{3}\times \frac{22}{7}\times (3.5)^2\times 8V=31×722×(3.5)2×8

V=\frac{1}{3}\times \frac{22}{7}\times 12.25\times 8V=31×722×12.25×8

V=102.66\ cm^3V=102.66 cm3

Therefore, the volume is 102.66 cm³.

#Learn more

If the circumference of the base of a right circular cone and the slant height are 120π and 10 cm respectively then find the curved surface area of the cone

Answer 2

$\huge \rm {Answer:-}$

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$\sf \red {Given\: Data:}$

Circumference of cone(c)=22 cm

Slant height (l)=8cm

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$\sf \blue {To\: Determine:}$

Curved surface of a cone=?

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$\sf \pink {We\: Know:}$

Curved surface area of a cone=πrl

radius(r)=?

Through circumference,we can find the radius

Circumference of a circular cone(c)=2πr

$\large \dashrightarrow \tt {22cm=2\times{\frac{22}{7}}\times r}$

$\large \dashrightarrow \tt {r=\frac{22\times7}{2\times22}}$

$\large \dashrightarrow \tt {r=\frac{\cancel{22}\times7}{2\times{\cancel{22}}}}$

$\large \dashrightarrow \tt \green{r=\frac{7}{2}cm}$

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$\sf \orange {Now,}$

Curved surface area=πrl

$\tt {r=\frac{7}{2}cm}$

$\tt {l=8cm}$

supplanting the given values,

$\large \dashrightarrow \tt {\frac{22}{7}\times{\frac{7}{2}}\times8}$

$\large \dashrightarrow \tt {\frac{22}{\cancel{7}}\times{\frac{\cancel{7}}{\cancel{2}}}\times{\cancel{8}}^{4}}$

$\dashrightarrow \tt {22\times4}$

$\implies \tt \green {Curved\: surface\: area=88cm^{2}}$

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$\sf \purple {Thence}$

Option-3 is the correct one.

The curved surface area of a right circular cone = $\tt {88cm^{2}}$