Question

The radius and height of a cylinder are in the ratio 2:7.If the volume of the cylinder is 704cm^3.Find the total surface area of the cylinder.

Answer 1

FORMULA FOR VOLUME OF CYLINDER = pi X r^2 X h

Let the height be 2x

Radius = 7x

Volume = pi X 49x^2 X 2x = 3.14 X 98x^3 = 8316

x^3 = 8316 / 3.14*98 = 27.024567 cm

x = 3 cm

HEIGHT = 6 cm Radius = 21 cm

FORMULA FOR TOTAL SURFACE AREA = 2pirh + 2pir^2

= 2pir ( r + h)

= 2 X 3.14 X 21 X 27 = 3560.76 cm^2

Answer 2

Step-by-step explanation:

let the ratio be x

radius = 2x

height =7x

volume = πr²h = 704

22/7 × 2x × 2x × 7x = 704

88x³ = 704

x³ = 8

x = 2

R=2x

2×2= 4

H=7x

7×2

14

total surface area = 2πr(h+r)

=2× 22/7 × 4 ( 14 +4)

=176/7 (18)

=3168/7

=452.57