Question

The circumference of a circle is 28meters. What is it’s radius

Answer 1

Circumference of the circle = 28 m

Circumference (formula) = 2πr

Thus,

`\sf{2\pi r = 28 \: m }`

`\sf{ (44r)/(7) = 28 \: m }`

`\sf{r \: = (28 * 7)/(44) \: m }`

After solving ,

`\sf{r = (49)/(11) \: m}`

After converting into mixed fraction,

`\sf{r = 4 (5)/(11) \: m \: }`

• Note 1 : If we want to write our answer is decimal form , we can write it as 4.45 m but this answer will be approximate.
• Note 2 : If we want to consider π as 3.14 then the answer will be a bit different but when we take it as 22/7 the answer is closer to the exact one.

Answer 2

Explanation:

Given

Circumference = 28 meters

2
`\pi r` = 28

2 * 3.14 * r = 28

r = 28 /6.28

Therefore r = 4.5 meter