Question

The radius and slant height of a cone are in the ratio 4: 7 if it's curved surface area is 792c^2 , fine its ?radius

Answer 1

Here is your answer.....

Answer 2

Given,

radius:slant height=4:7

Curved Surface Area of cone=792cm2

Let the radius of cone be 4x and slant height be 7x

Now, According to question,

Curved Surface Area= pi*r*l

=>792=22/7*4x*7x

=> 792*7/22=28x2

=> 36*7/28 =x2

=> 4*9*7/7*4= x2

=> 9=x2

=> plus/minus3=x

Since radius cannot be negative,

=>x=3

Therefore The required answer,

Radius= 4*x=4*3=12 cm

Hope it helps!