Question

the difference of areas of two concentric circles is 770 cm² and the difference of their radii is 7 cm. Find the radius of each circle.​

Answer 1

Answer:

Let the radius of inner circle be r.

Area enclosed between two concentric circles

⇒ π[(21)2 – (r)2] = 770

⇒ (21)2 – (r)2 = 770/π = 770 × 7/22

= 35 × 7

⇒ (21)2 - (r)2 = 245

⇒ 441 – r2 = 245

⇒ 441 – 245 = r2

⇒ 196 = r2

⇒ 14 = r

The radius of inner circle = 14 cm.

Step-by-step explanation:

IHOPE IT HELP YOU

Answer 2

Step-by-step explanation:

Radius of outer circle =21cm

Radius of inner circle =14cm

I hope it is helpful to you

If any problem comment below