# Trigonometry,Pythagoras and Circle Theorem Question

• May 3rd 2010, 08:42 AM
Metalingus
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)

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. :)
• May 3rd 2010, 04:51 PM
skeeter
shaded area = area of the sector - area of the triangle

area of a sector = $\displaystyle \frac{r^2 \theta}{2}$ , where $\displaystyle \theta$ = measure of the central angle in radians

you mentioned nothing about the triangle ... is it isosceles, a right triangle ... what ???
• May 3rd 2010, 04:59 PM
Debsta
Quote:

Originally Posted by Metalingus
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)

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. :)

Are 2 vertices of the triangle meant to be on the circumference of the circle?