# Just checking to see if right and how to get arc.

• Jul 11th 2007, 02:48 PM
sanee66
Just checking to see if right and how to get arc.
Just wondering if I proved the congruency part right and how do I answer the second part? Still confused over previous post. Is the arc 45 degrees? Took forever to get this to upload!

Theorem 2 says that if two chords are parallel, then the arcs between them are congruent. Arcs AE and BF are between the parallel chords AB and EF so this makes arcs AE and BF congruent. It says that the arcs between EF and CD are congruent. This makes arcs EC and FD congruent so the total arcs of AC and BD are congruent. Since all lines are parallel and all other arcs are congruent then the arcs between AB and CD are congruent.
• Jul 11th 2007, 06:49 PM
topsquark
Quote:

Originally Posted by sanee66
Just wondering if I prved the congruency part right and how do I answer the second part? Still confused over previous post.

Just checking here...

Are you psychic? I know I'm not.

:confused: What problem are you talking about??? Perhaps you should try posting in the original thread next time. That way you might just get an answer.

-Dan
• Jul 11th 2007, 11:11 PM
red_dog
Let $arc \ CD=x$. Then $arc \ AB=2x$.
$arc \ AC=arc \ BD=105$.
We have $x+2x+2\cdot 105=360\Rightarrow 3x=150\Rightarrow x=50$