Question

Find the diamter of a circle if its area is 706.9mm²​

Answer 1

30mm

Explanation:

A=
`\pi`
`r^(2)`

Substitute 706.9 for A and
`\pi` for 3.14

706.9= 3.14
`r^(2)` divided both sides by 706.9

when you divided 3.14 by 3.14 it will cross and when you divide 706.9 by 3.14 it will give you 225.

`√(225)`

15 times 15 is 225

radius= 15

d=2r

multiply 15 by 2

the answer is 30.

Answer 2

30 mm

Explanation:

The formula of an area of a circle:

`A=\pi r^2`

r - radius

We have

`A=706.9\ mm^2`

Substitute:

`\pi r^2=706.9` divide both sides by π

`r^2=(706.9)/(\pi)` use π ≈ 3.14

`r^2\approx(706.9)/(3.14)\\\\r^2\approx225\to r=√(225)\\\\r= 15\ mm`

The diameter d = 2r.

Therefore

`d=2(15)=30\ mm`