# Math Help - How to calculate perimeter of a triangle, tricky one?

1. ## How to calculate perimeter of a triangle, tricky one?

Hello, I would like to ask a question which I can't figure out by myself, I'll skip chatter and shoot it:

I need to calculate the length of the perimeter of the circle, but I don't know how I can do that when no lengths at all have been given, so please advise.
This is how I progressed: Aijaa.com - 5598188.jpg

Oh, and I have a 9 hour deadline on this, starting now :X

2. Your problem can't be solved in terms of numercial lengths as you only have an angle to begin with.

3. Oh god I missed something, also the radius of the circle was given (r=12cm) :l Shouldn't do these things when I'm tired, but what did we learn? Read the description!

4. Originally Posted by mazzuli
I need to calculate the length of the perimeter of the circle,
Also known as the circumference you have the formula

$C = 2\pi r$

Originally Posted by mazzuli
also the radius of the circle was given (r=12cm)
In your case

$C = 2\pi r$

$C = 2\times \pi \times 12$

Now reach for your calculator..

5. Yeah thanks for the help, although I would have figured it out if I would have bothered to read the description of the task at hand. Now that I've slept over the night, I came to think how much mistakes I made yesterday, and not only regarding maths.. And even my cellphone is screwing with me, didn't wake me up and now I'm gonna be late for school.. Well, atleast it's gonna be a music lesson I'm gonna be late from, so nothing too important. This week isn't really going too well for me