Question

A circular photo frame has an outer radius
20 cm and inner radius 18 cm. Find the
width of the frame around the photo.
Also find the cost of painting it with a
metallic colour at the rate of 0.7 per cm sq. ........


(answer of this question is 2cm and rupees. 167.20​

Answer 1

Step-by-step explanation:

Width of frame= circumference of outer cirlce-inner circle

C of outer circle=2πr

=2×22×20

7

=125.71 cm

C of inner circle=2πr

=2×22×18

7

=113.14 cm

Width= circumference of outer cirlce-inner circle

=125.71 - 113.14

=12.57 cm

Cost =12.57×0.7

=Rs.8.799

Sorry for giving late

Answer 2

Answer:

167.2

Step-by-step explanation:

1.outer circle-inner circle

phi*20*20-phi*18*18

=400phi-324phi

=76phi is the area we need to paint with

so multiply the value by 0.7

hence the answer is 167.2