Question

Look at the formula for the area of a circle below.

A = 3.14(pi)r2

Which of the following equations can be used to solve for the radius (r)?

Answer 1

\[A=\pi r2\]

Answer 2

orrr \[\pi r ^{2}\]

Answer 3

Well area of a circle is \(\pi r^2 \) so you can use that to find r if the area has been given

Answer 4

What equation can be used to solve for the radius (r)?

Answer 5

C = 2 Pi r
divide both sides by 2*Pi
C/(2 * Pi) = r

Answer 6

\[\huge A=\pi r^2 \ \ \text{which is the area of a cirlce} \]\[\huge C=2\pi r \ \text{circumference of a circle} \]

Answer 7

you basically have to make r the subject :)

Answer 8

So R=?

Answer 9

if area is given, then
\[\huge r=\sqrt{\frac{A}{\pi}} \]
and when you have the circumference given,
\[\huge r=\frac{C}{2\pi} \]

Answer 10

ohhhh i see

Answer 11

:)