Question

An arc of a circle subtends an angle of 90° at the centre. The ratio of the area of the major sector to that of the minor sector is ___________.l​

Answer 1

Step-by-step explanation:

The area enclosed between the concentric circles is 770 cm2. If the radius of the outer circle is 21 cm, find the radius of the inner circle.

ANSWER:

Let the radius of outer and inner two circles be r1 and r2 respectively.

Area enclosed between concentric circles = πr12−πr22

⇒770=227(212−r22)⇒245=212−r22⇒r22=441−245⇒r22=196⇒r22=142⇒r2=14 cm

Hence, the radius of inner circle is 14 cm

Answer 2

Answer:

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