The radii of two circles are 9 cm and 12 cm. The circumference of a circle whose area is equal to sum of the areas of the two circles is:

15

No worries! We‘ve got your back. Try BYJU‘S free classes today!

15 π

No worries! We‘ve got your back. Try BYJU‘S free classes today!

30 π

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

225 cm

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is B $30 π$ cm
Area of first circle $= 81 π$
Area of 2nd circle $= 144 π$
Area of 3rd circle $= 255 π$
Let radius of 3rd circle $= R$
$∴ π R^{2} = 225 π$
$R^{2} = 225$
$R = 15$
$∴$ Circumference $= 2 \times π \times 15 = 30 π$ cm.

Suggest Corrections

Similar questions

The diameter of a circle whose area is equal to the sum of the areas of the two circles of radii 40 cm and 9 cm is:

Find the diameter of a circle in cm whose area is equal to the sum of the area of the two circles of radii 24 cm and 7 cm.

40 c m

9 c m

Join BYJU'S Learning Program