Question

a) the ratio of the raddi of two circles is 3 : 2 find the ratio of their areas.
b) the area of two circles are in the ratio 4 : 9. find the ratio of their circumferences ​

Answer 1

Answer:

First of all,

The area of Circle is

$\pi {r}^{2}$

The circumference of Circle is

$2\pi \: r$

Step-by-step explanation:

Part a) Ratio of raddi of two circle is 3:2

it means the radii of two circles are 3cm and 2cm

respectively.

Ratio of the area of two circles:

area of first circle 22/7×3×3 = 198/7 = 28.28 cm^2 approx

area of second circle 22/7×2×2 = 88/7 = 12.57cm^2 approx.

Ratio =

$\frac{2828 \times 100}{1257 \times 100}$

$\frac{2828}{1257}$

You can convert this into Standard form but if you leave this as it is then also this is correct.

Part b) Ratio or raddi of two circles is 4:9

Ratio of the circumference of two circles:

Circumference of first circle 2×22/7×4

176/7 = 25.14cm

Circumference of the second circle 2×22/7×9

396/7 = 56.57cm

Ratio =

$\frac{2514 \times 100}{5657 \div \times 100}$

$\frac{2514}{5657}$

Thankyou