Question

Find the radius of a circle that has a circumference of 340 cm.

Answer 1

Hey there :)

We know the formula of the circumference of a circle:
Circumference = 2
`\pi` × radius

We are given;
The circumference = 340 cm

Apply the formula
340 = 2
`\pi` r

Divide by 2
`\pi` on either side

`(340)/(2 \pi ) = (2 \pi r)/(2 \pi )`

`(170)/( \pi ) = r`

r ≈ 54.1 cm → Your answer

Answer 2

The formula for the circumference of a circle is C = 2
`\pi`r

So we just plug in the given information and work backwards.

340 = 2
`\pi`r.

Divide by 2
`\pi` to isolate the variable r.

r = 340 / 2
`\pi`

radius = 170
`\pi` or the radius is ≈ 534.071 cm.