Question

find the curved surface area and the total surface area of a cylinder whose volume is 1.54 m and radius of the base is 70 cm

Answer 1

$\Longrightarrow{\boxed{\bold{Answer:4.4\:m^2}}}$
$\Longrightarrow{\boxed{\bold{7.48\:m^2}}}$

$\textbf{\underline{Step-by-step explanation :- }}$

Volume of cylinder = πr²h

1.54 m³ = π(70)²h

Since, 1 cm = 1/100 m

70 cm = 70/100 m = 0.7 m

1.54 m³ = π(0.7)²h

1.54/0.49 = πh

3.14 ( approx ) = πh

3.14 × 7/22 = h

$\textbf{1 m ( approx ) = height }$

Curved surface area of cylinder = 2πrh

= 2 × 22/7 × 0.7 m × 1 m

= 2 × 22 × 0.1 × 1

$\bold{\huge{=\underline{4.4\:m^2}}}$

Total surface area of cylinder

= 2πr( h + r )

= 2 × 22/7 × 0.7 m ( 0.7 + 1 ) m

= 2 × 22 × 0.1 m × 1.7 m

$\bold{\huge{=\underline{7.48\:m^2}}}$