Question

the area enclosed by the circumference of two concentric circles is 423.5cm square . If the circumference of outer circle is 132 cm . Calculate the radius of the inner circle​

Answer 1

Answer:

17.5

Step-by-step explanation:

circumference of circle = 2pi r

132 = 2 ×22/7 × r

r= 21

Area of the between two circles is = A2-A1

( AREA OF THE CIRCLE = PI R ^ 2

= PI R1 ^2 - PI R2^2

= 22/7 × 21^2 - 22/7 × R2^2 ( 'R2 = 21)

= 17.5