Question

What is the circumference of a circle with an area of `49 pi` `i``n``ches^2`?

Answer 1

`44` `i` `nches`

Explanation:

`Let` `radius` `o` `f` `ci` `rcl` `e` `=` `r`
`Area` `o` `f` `cir` `c` `l` `e` `=` `pir^2=49pi` `i` `nches^2`

`Note` `th` `at` `pi=22/7`

`rarrpir^2=49pi`

`rarrr^2=(49pi)/pi`

`rarrr^2=49`

`rarrr=sqrt49=7`

`So,we` `n` `eed` `t` `o` `fi` `nd` `ci` `rcu` `mf` `erence` `o` `f` `ci` `rcl` `e`

`Ci` `rcumference` `o` `f` `ci` `rcl` `e` `=2pir`

`rarr2pir=2pi(7)=14pi`

`rarr=14*22/7=2*22=44` `i` `nches`

Answer 2

`C = 14pi = 43.982 ~~44` inches

Explanation:

To find the circumference, you need the radius.

You can find the length of the radius from the area.
(Divide by `pi` and then find the square root)

`pi r^2 =A" "rarrr = sqrt(A/pi)`

The radius is `r = sqrt((49cancelpi)/cancelpi)`

`r = sqrt49 = 7` inches

`C=2pir`

`C = 2pi(7)`

`C=14pi`

You can give the answer in this form using `pi` because that is how the area was given,

Or if you calculate it:

Using `pi ~~ 22/7`

`14 xx22/7`

`= 44` inches

Using the calculator value of `pi` which is more accurate gives:

`14pi =43.982` inches