Question

The radii of two circles are in the ratio 4:5. Find the ratio of their:
(i) circumferences (ii) areas​

Answer 1

Answer:

let the radii of the two circles be 4x and 5x

Answer 2

Answer :

• Area = 16 : 25
• Circumference = 4/5

Given :

• The radii of two circles are in the ratio 4:5

To find:

• circumference
• areas

Solution :

Area :

Given radii are in the ratio 4 : 5

• let the radii of first radio be 4x
• let the radii of second ratio be 5x

As we know that

• Areas are in the ratios

⟾ π(4x)² : π(5x)²

⟾ 16x²π : 25x²π

Remove x² and π

⟾ 16 : 25

Hence Area are in the ratio is 16 : 25

Circumference :

Given that ,

• Ratio of radii 2 circles is 4 : 5

• let the radius be 4x and 5x

Ratio of their circumference:

⟾ 2π/2π 4x/5x

Remove 2π and x

⟾ 4/5

Hence Circumference is 4/5

• Area = 16 : 25
• Circumference = 4/5