Question

radius of a base of a cylinder and its height are r = 2.5 cm , h = 7cm find the curved surface and total surface area​

Answer 1

Answer:

Given :-

• A cylinder whose radius of a base of a cylinder and its height are 2.5 cm and 7 cm respectively.

To Find :-

• What is the curved surface area and total surface area of a cylinder.

Solution :-

☆ In case of curved surface area of a cylinder :

Given :

• Radius = 2.5 cm
• Height = 7 cm

According to the question by using the formula we get,

$\implies \sf\boxed{\bold{C.S.A._{(Cylinder)} =\: 2{\pi}rh}}$

where,

• C.S.A. = Curved Surface Area
• r = Radius
• h = Height

By putting those values we get,

$\implies \bf C.S.A._{(Cylinder)} =\: 2{\pi}rh$

$\implies \sf C.S.A._{(Cylinder)} =\: 2 \times \dfrac{22}{7} \times 2.5 \times 7$

$\implies \sf C.S.A._{(Cylinder)} =\: \dfrac{44}{7} \times 17.5$

$\implies \sf C.S.A._{(Cylinder)} =\: \dfrac{770}{7}$

$\implies \sf\bold{\underline{C.S.A._{(Cylinder)} =\: 110\: cm^2}}$

$\therefore$ The curved surface area of a cylinder is 110 cm² .

☆ In case of total surface area of a cylinder :

Given :

• Radius = 2.5 cm
• Height = 7 cm

According to the question by using the formula we get,

$\implies \sf\boxed{\bold{T.S.A._{(Cylinder)} =\: 2{\pi}r(r + h)}}$

where,

• T.S.A. = Total Surface Area
• r = Radius
• h = Height

By putting those values we get,

$\implies \bf T.S.A._{(Cylinder)} =\: 2{\pi}r(r + h)$

$\implies \sf T.S.A._{(Cylinder)} =\: 2 \times \dfrac{22}{7} \times 2.5(2.5 + 7)$

$\implies \sf T.S.A_{(Cylinder)} =\: \dfrac{44}{7} \times 2.5(9.5)$

$\implies \sf T.S.A._{(Cylinder)} =\: \dfrac{44}{7} \times 23.75$

$\implies \sf T.S.A._{(Cylinder)} =\: \dfrac{1045}{7}$

$\implies \sf\bold{\underline{T.S.A._{(Cylinder)} =\: 149.28\: cm^2}}$

$\therefore$ The total surface area of a cylinder is 149.28 cm² .

Answer 2

Answer:

A cylinder was radius of a base of a cylinder and it's hight are 2.5 cm and 7cm respectively