Question

3. The height of a cone is 15 cm. If its volume is 1570 cm3, find the radius of the base.
(Use \piπ = 3.14)
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Answer 1

☯ Given that,

• Height of a cone (h) = 15 cm
• It's volume (V) = 1570 cm³
• Value of π = 3.14

☯ To Find,

• The radius of the base.

ㅤㅤ_________________

According to the question,

Volume of cone = ¹/3 × πr²h

⇒ 1570 = ¹/3 × 3.14 × r² × 15

⇒ 1570 = 3.14 × r² × 5

⇒ 1570 = r² × 15.7

⇒ r² = 1570/15.7

⇒ r² = 100

⇒ r = 10 cm

Hence,

Radius of the base is 10 cm.

☯ Know to more:

• Curved surface area of cone = πrl
• Total surface area of cone = πr(l + r)
• Volume of cylinder = πr²h
• Total surface area of cylinder = 2πr(r+ h)
• Curved surface area of cylinder = 2πrh

Answer 2

$\Huge\tt{{\color{navy}{{\underline{AN}}}}{\color{blue}{{\underline{SW}}}}{\blue{{\underline{ER}}}}{\color{skyblue}{:}}}$

$\huge\color{navy}{\textbf{\textsf{GIVEN :-}}}$

• Height of a cone (h) = 15 cm
• Volume (V) = 1570 cm³
• Value of π = 3.14

$\huge\color{blue}{\textbf{\textsf{TO FIND :-}}}$

• The radius of the base.

$\huge\color{skyblue}{\textbf{\textsf{SOLUTION :-}}}$

Volume of the cone = 1/3 × πr²h

→ 1570 = 1/3 × 3.14 × r² × 15

→ 1570 = 3.14 × r² × 5

→ 1570 = r² × 15.7

→ r² = 1570/15.7

→ r² = 100

→ r = 10 cm

Hence, the radius of the base is 10 cm.

Hope it Helps Buddy ♥️