Question

The area of a circular ring enclosed between the two concetric circles is 286cm^2 find the diameters if their difference is 14 cm

Answer 1

Answer:

Let R and r is the radii of outer and inner circle respectively.

a/c to question,

R -r = 7 cm --------------(1)

πR² -πr² = 286 cm²

π(R -r)( R + r ) = 286 cm ²

22/7 × 7 (R + r) = 286 cm²

(R + r) = 13 ---------(2)

from equation (1) and (2)

R =10 cm

r = 3 cm