Question

The ratio of the radius and height of a cylinder is 2:3 if it's total surface area is 277.2cm sq find its radius and height

Answer 1

Answer:

r= 4.2 cm , h=6.3 cm

Step-by-step explanation:

Let the radius be 2x and height be 3x.

Now we know that TSA of cylinder= 2πrh+ 2(πr²)

Substitute r and h values in the formula.

2π(2x)(3x)+ 2π(2x)² = 277.2

12x²π+ 8x²π = 277.2

x²= 277.2/π × 1/20

x²= 4.41

x= 2.1

Now radius = 2.1 × 2 = 4.2cm

height = 2.1* 3 = 6.3cm.