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 c m

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

15 π c m

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

30 π c m

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

225 c m

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

Open in App

Solution

The correct option is C $30 π c m$
Area of first circle = $81 π$
Area of 2nd circle = $144 π$
Area of 3rd circle = $225 π$ [Sum of area of two circles]
Let radius of 3rd circle = R
$∴ π R^{2} = 225 π$
$R^{2} = 225$
$R = 15$
$∴ C i r c u m f e r e n c e = 2 \times π \times 15 = 30 π c m$

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:

The radii of two circles are 19 cm and 9 cm respectively. Find the radius and area of the circle which has its circumference equal to the sum of the circumferences of the two circles.

Q. What is the diameter of a circle whose area is equal to the sum of the areas two circles of radii

40 c m

and

9 c m

The radii of two circles are 19 cm and 9 cm respectively. The radius of the circle which has its circumference equal to the sum of the circumferences of the two circles is:

Q. The area of the circle varies directly as the square of its radius. Find the radius of circle whose area is equal to the sum of the areas of two circles whose radii are 5 cm and 12 cm.

Join BYJU'S Learning Program

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:

The correct option is C 30 π cmArea of first circle = 81π Area of 2nd circle = 144π Area of 3rd circle = 225π [Sum of area of two circles] Let radius of 3rd circle = R ∴πR2=225π R2=225 R=15 ∴Circumference=2×π×15=30πcm

The correct option is C $30 π c m$
Area of first circle = $81 π$
Area of 2nd circle = $144 π$
Area of 3rd circle = $225 π$ [Sum of area of two circles]
Let radius of 3rd circle = R
$∴ π R^{2} = 225 π$
$R^{2} = 225$
$R = 15$
$∴ C i r c u m f e r e n c e = 2 \times π \times 15 = 30 π c m$