Question

the diameter of the base of right circular cylinder is 18.2cm and the ratio of the area of its curve surface to the area of the base is 15:13.find the total surface area of the cylinder​

Answer 1

Step-by-step explanation:

r=9.1

csa=15/13×22/7×9.1×9.1

=300.3

Answer 2

Total surface area of the cylinder = 817.2164 sq cm

Step-by-step explanation:

• The diameter of the base of the cylinder = 18.2 cm

It means, the radius = 9.1 cm

• The ratio of its curved surface area to the base area = 15:13

We know that the curved surface area of cylinder (CSA) = $2\pi rh$

Where; r = radius, h = height

• Also, the base area of right circular cylinder = $\pi r^2$

Here, r = radius

According to the question, we write as;

• $\dfrac{2\pi rh}{\pi r^2} = \dfrac{15}{13}$

        h = $\dfrac{136.5}{26}$= 5.25 cm

• Now, we can find out total area of cylinder = $2 \pi r^2 + 2 \pi rh$

• Total area of cylinder = $2 \times 3.14 \times (9.1)^2 + 2 \times 3.14 \times (9.1) \times 5.25$

        = 817.2164 sq cm

Thus, total surface area of the cylinder = 817.2164 sq cm