Question

If any figure, two circles with the same centre are shown. The radius of the outer circle is 12 cm, whereas the radius of the inner circle is 8 cm. Find:

(i) The area of the outer circle (ii) The area of the inner circle (iii) The area between both circles​

Answer 1

Area if outer circle = π×12×12= (22/7) ×12×12=452.57

Area of inner circle = π×8×8= (22/7) ×8×8 = 201.14

Area between both circles = area of outer circle - area of inner circle =452.57-201.14=251.43

Answer 2

Step-by-step explanation:

According to question,

Radius of larger circle is 5cm

and length of tangent AC to smaller circle is 8cm.

We know that, tangent is perpendicular to radius through point of tangency,

And M, is the mid point of tangent from figure,

so AM=4cm

Therefore,

AAMO is the right angle triangle, with OM as radius of smaller circle,

So, from pythagorous theorem,

OA

2

=OM

2

+AM

2

=> 5 ↑

2

=OM

2

+4

2

=> OM=3

=> Hence radius of smaller circle =3cm

b)

area of the outer circle = π * ²

area of the outer circle = 22/7 * 12² = 452.57 sq. cm.

area of the inner circle = π * p²

area of the inner circle = 22/7 * 82 =201.14 sq. cm.

area between both circles

= area of the outer circle of the inner circle - area

= 452.57 - 201. 14

= 251.42 sq. cm