Question

Find the curved surface area and total surface area of a right circular cylinder of height 15 cm and whose base radius is 7 cm.

Answer 1

Hint: In this question it is given that we have to find the curved surface area(CSA) and total surface area(TSA) of a right circular cylinder of height 15 cm and whose base radius is 7 cm. So to find the solution we need to know the formula,
CSA=$$2\pi rh$$...................(1)
TSA=$$2\pi r\left( h+r\right) $$......(2)
Where h= height of cylinder , r= radius of cylinder.

Complete step-by-step solution:
Given the radius(r) = 7 cm and height(h) = 15 cm.
Therefore by equation (1), the curved surface area of the given cylinder,
CSA=$$2\pi rh$$
   =$$2\times \dfrac{22}{7} \times 7\times 15$$ [since $$\pi =\dfrac{22}{7}$$]
   = 660 $cm^{2}$
And the total surface area,
TSA=$$2\pi r\left( h+r\right) $$
   =$$2\times \dfrac{22}{7} \times 7\left( 15+7\right) $$
   =$$2\times 22\times 22$$= 968 $cm^{2}$
Hence, the Total surface area of the circular cylinder is 968 $cm^{2}$ and the Curved surface area is 660 $cm^{2}$.

Note: For a cylindrical shape, if it is not mentioned whether the given cylinder is opened or closed, then you have to consider the given cylinder as a closed one and also the total surface area includes the curved surface area and the area of upper and lower circular face of the cylinder.