Question

A circle is 16л cm². What is the circle's circumference? 2л cm 4л cm 8л cm 16л cm​

Answer 1

Option 3

Explanation:

`A=\pi r^2 = 16\pi \\ \\ r^2 =16 \\ \\ r=4 \\ \\ \implies C=2\pi r=2\pi (4)=8\pi`

Answer 2

8π cm

Explanation:

Hello!

Area of a Circle:
`A = \pi r^2`

Circumference of a Circle:
`C = 2\pi r`

We first have to find the radius, r.

Find R

• 
  `A = \pi r^2\\A = 16\pi^`
• 
  `\pi r^2 = 16\pi`
• 
  `r^2 = 16`
• 
  `r = 4`
  `\hookrightarrow` Take positive value

Now, we can find the circumference, given the radius.

Find the Circumference

• 
  `C = 2\pi r`
• 
  `C = 2\pi (4)`
• 
  `C = 8\pi`

The circumference is 8π cm.