Question

The area of a circle
what is a diameter of a circle?

Answer 1

You can find the area by using the formula: S = πr². In this case, r = 4, π = 3.14, so the area equals to 3.14 * 16 = 50.24.

Answer 2

The area is:

50.24 cm²

Work/explanation:

The formula for a circle's area is:

`\boxed{\!\!\boxed{\quad\sf{A=\pi r^2\quad}}\!\!}`

where,

A = area

π = 3.14

r = radius

Diagram:

`\setlength{\unitlength}{1cm}\begin{picture}(0,0)\thicklines\qbezier(2.3,0)(2.121,2.121)(0,2.3)\qbezier(-2.3,0)(-2.121,2.121)(0,2.3)\qbezier(-2.3,0)(-2.121,-2.121)(0,-2.3)\qbezier(2.3,0)(2.121,-2.121)(-0,-2.3)\put(0,0){\line(1,0){2.3}}\put(0.5,0.3){\bf\large 4\ cm}\end{picture}`

Now to solve further, plug in the data from the problem:

`\Large\begin{gathered}\sf{A=\pi r^2}\\\sf{A=3.14*4^2}\\\sf{A=3.14*16}\\\sf{A=50.24\:cm^2}\end{gathered}`

And we get that A = 50.24 cm².