Question

if the radius and slant height of a cone are in the ratio 7 :13 and its curved surface area is 286 CM2 find its radius​

Answer 1

Answer:

radius=7√3 cm

Step-by-step explanation:

what's given :

radius(r)=7x

slant height(l)=13x

curved surface area of a cone=286cm^2

what's to be find:

radius=?

method:

formula for finding C.S. area

=1/3 πrl

=1/3(22/7)*7x*13x

=(286/3)*x^2.................(1)

by given data C.S.A=286

(286/3)*x^2=286

x^2=3

x. =√3

....by substituting x =√3 value in radius

• radius=7√3

Answer 2

Answer:

Let r/1 = 7/13x

Curved surface area CSA=286 cm2

But CSA=πrl

∴286 = 22/7 × 7x × 13x

or x2 = 286/22×13 = 1

or x = 1

∴ r=7 cm

∴ Diameter d=14 cm