Compare Circle Areas: Finding Area Ratio of 4 cm vs 10 cm Radius Circles

The area of a circle is calculated using the following formula:

where r represents the radius.

Using the formula, we calculate the areas of the circles:

Circle 1:

$π\cdot4² =$

$π16$

Circle 2:

$\pi\cdot10²=$

$π100$

To calculate how much larger one circle is than the other (in other words - what is the ratio between them)

All we need to do is divide one area by the other.

$\frac{100}{16}=$

$6\frac{1}{4}$

Therefore the answer is 6 and a quarter!