Question

Two circles touch each other internally. The

radius of the smaller circle is 6 cm and the distance
between the centre of two circles is 3cm. The radius
of the larger circle is
a) 7.5cm
b) 9cm
c) 8cm
d) 10cm

Answer 1

• 
  `\sf b) \: 9 \: cm`

Explanation:

We have been given that Two circles touch each other internally. The radius of the smaller circle is 6 cm and the distance between the centre of two circles is 3cm.

Refer to the attachment.

From figure,

• The radius of the smaller circle (AB) = 6 cm
• The distance between the centre of two circles (OA) = 3cm.

The radius of the larger circle (OB) = radius of the smaller circle (AB) + distance between the centre of two circles (OA)

`\rm OB = AB + OA`

`\rm OB = 6 + 3`

`\rm OB = 9 cm`

Henceforth, The radius of the larger circle is 9 cm.