Question

the area enclosed by two conecentrie circles is 330sq cm.If the radius of the smaller circle is8cm,then find the radius of the bigger circle.

Answer 1

Step-by-step explanation:

area of circle 1 + area of circle 2= 330sq

$\pi r1 {}^{2} : + \pi \: r2 {}^{2}$

22/7×8^2+22/7×r2^2

22/7(64+r^2)=330

64+r^2=104

r^2=104-64

r=root40

Answer 2

Heyya :)

770 = π R²- π r²

= π (R² -r² ) taking π common

770/π =21² -r²

770 × 7/22 = 441 - r²

45 - 441 = -r²

-r² = -196

r = 14