# Circle theroems.

• Nov 6th 2008, 11:07 AM
knightley101
Circle theroems.
im lost, completely, ermm, please find enclosed is a image of my question, could you please explain what to do, and how to do it.

thanks

http://img204.imageshack.us/my.php?image=grrmv6.jpg
• Nov 6th 2008, 11:26 AM
Laurent
Quote:

Originally Posted by knightley101
im lost, completely, ermm, please find enclosed is a image of my question, could you please explain what to do, and how to do it.

thanks

ImageShack - Hosting :: grrmv6.jpg

Finding b and c is very easy (no computation): remember that an arc of a circle is viewed with the same angle from every point on the circle. I'm not sure this is correct English, but anyway you must have learned it. On the picture, the arc intercepted by the angle b is also intercepted by another angle that you are given... hence b is equal to this other angle.

As for the angle d, I think you have to use a few times the fact that the sum of the angles of a triangle is 180°, and perhaps the fact that the sum of the angles around a point is 360°.