# math

posted by
**christina** on
.

the radius of a circle when the numeric values of the circumference and area are equal.

circumference = 2*pi*r

area = pi*r^2

Set them equal and solve for r.

thanks! i understand it now!

2*3.14*r=3.14*r^2

6.28*r=3.14*r^2

r=3.14

Is that right? It doesn't seem to be.

2*3.14*r=3.14*r^2

6.28*r=3.14*r^2 **You are ok to here. **

r=3.14

Is that right? It doesn't seem to be.
**Then divide both sides by 3.14
(6.28/3.14)*r=(3.14/3.14)r^2
2*r=1*r^2
Now divide both sides by r
2*(r/r)=(r^2/r)
2*1=r
2=r**

*But there is an easier way to have done it. Start at the beginning and we have*

2*pi*r=pi*r^2

The pi cancels since it is on both sides.

Divide both sides by r to obtain

2=r

2*pi*r=pi*r^2

The pi cancels since it is on both sides.

Divide both sides by r to obtain

2=r

I hope this helps.

thanks, it did help!!

the diameter of a bicycle wheel is 26 in. How far will you travel after one complete turn of the wheel?