Find the Radius...Find the free online calculator

[mathmarauder]

I have looked for free online calculators and I have found a bunch.
The question is; what do I need the calculator for?
I have been asked to find the radius of a cricle that has a central
angle of 135 degrees. The arc length is 8.
What I did so far was
135 degrees is 3/8 of 360 degrees
3/8 = .375
8/.374 = 21.33
so the circumference is 21.33
radius = 21.33/2pi
and it seems on the calculator im using, everytime i hit the pi button, Pi comes up
but doesnt do anything else. Unsure if im making sense.
I just need a free online calculator that will let me type in 21.33/2pi and give me the answer
Thank you for any assistance

 

[galactus]

The formula is \(\displaystyle s=r{\theta}\)

Remember, the angle must be in radians. So, 135 degrees is \(\displaystyle \frac{3\pi}{4}\) radians.

\(\displaystyle 8=\frac{3\pi}{4}r\)

Now, use any calculator to divide \(\displaystyle \frac{8}{\frac{3\pi}{4}}=\frac{32}{3\pi}\approx 3.395\)

Now, can you use some calculator to solve it?.

If nothing else, just type in 3.14 for pi instead of finding the pi button.

 

[mathmarauder]

Thank you for the help

 

[Denis]

radius = 21.33/2pi
.....and it seems on the calculator im using, everytime i hit the pi button, Pi comes up
but doesnt do anything else.

Well, get Pi to come up, multiply it by 2, then store results;
then divide (21 + 1/3) by the stored amount....