Trigonometry,Pythagoras and Circle Theorem Question

http://i41.tinypic.com/rrjqiv.png

I'm stuck on this question, trigonometry is the only thing in math that I really don't get.

Some information for you:

The angle in the triangle is 15 degrees if that's not clear.

I need to find the area of the space between the edge of the triangle and the circle.

That triangle is meant to start from the middle of the circle.

I know that there is 24 of the triangles in the circle.

Circumference of the circle is 40cm

Diameter is 12.73(2 decimal places)

Radius is 6.34

I would like to know how to solve this, what the steps are so you don't just say i did this got this and then bam! Theres your answer.

I want the whole lot, but step by step so I can still work it out.

For example: Instead of you saying the diameter is 12.73 you say ...next you need to work out the diameter by doing the circumference/pi. not 40/pi=12.73.

Thanks (Hi)

(That drawing is very rough, So it is definantly not to scale)

Edit:

Just noticed you don't help with things counting towards final grades so I thought I should point out that this is just a piece of homework. Doesn't count for anything, our reports have already been done. :)