Question

Find area of cylinder if external radius is 20cm and internal radius is 15 cm.

Answer 1

Answer: question lacks data , height of cylinder is not mentioned .

here R = 20cm ,r = 15cm

Step-by-step explanation:

Area of cylinder

= 2π [(R + r)H + (R^2 - r^2) ]

= 2π[ (20+15)H + (20^2 - 15^2)]

= 2π(35H + 175)

= 44/7(35H + 175) cm^2

put value of H here and get the Answer