Question

Two concentric circlesradius 17 and 7cm find the area of ring

Answer 1

Step-by-step explanation:

Smaller radius, r = 7cm,

Larger Radius, R= 17 cm.

Area of Ring= πR²- πr²,

which is factorised as:-

π(R+r)(R-r),

Substituting the values, I get,

area of the ring =

$3.14 \times (17 + 7)(17 - 7) \\ = 3.14 \times 24 \times 10 \\ = 31.4 \times 24 \\ = 753.6 \: {cm}^{2}$

That's the correct answer.