Question

Find the ratio of the surface areas of two cones if their radii of the bases are equal and slant heights are in the ratio 2 : 3.

Answer 1

Answer:

area is =πrl

ratio is

=πrl/πrl'

=l/l'

=2/3

Answer 2

Step-by-step explanation:

Curved surface area of cone

$CSA= \pi \: r \: l$

Let the radius of cone 1 is r1 and slant height is l1 and radius of cone 2 is r2 and slant height is l2.

According to the question

$r_1 = r_2 \\ \\ \frac{l1}{l2} = \frac{2}{3}$

So, ratio of their CSA are

$\frac{CSA_1}{CSA_2} = \frac{\pi \times \: r_1 \times l_1}{\pi \times r_2 \times l_2} \\ \\ = \frac{\pi \times \: r_1 \times l_1}{\pi \times r_1 \times l_2} \\ \\ = \frac{l_1}{l_2} \\ \\ \frac{CSA_1}{CSA_2} = \frac{2}{3}$

Hope it helps you.