geometrykid said:
EDIT:: MEASURE OF ANGLE 5! SORRY D:
Given: angle 4 and angle 6 are supplementary
Prove: measure of angle 4 = measure of angle
5
2 column proof.
here's the diagram:
http://i36.tinypic.com/9riqua.png
click it .
THANKS ;]
I'm not going to write a two-column proof for you. But I will give you some clues which I hope will enable you to write the proof yourself.
You are GIVEN that angles 4 and 6 are supplementary.
Now, look at the diagram. Do you see that angles 5 and 6 form a LINEAR PAIR? I don't know about
your textbook, but all of the geometry textbooks I taught out of for the past 30 years or so had something called the "Linear Pairs Postulate" which said basically this: If two angles form a linear pair, then those angles are supplementary.
Using the Linear Pair Postulate, then, we can say that angles 5 and 6 are supplementary.
So...angles 4 and 6 are supplementary, and angles 5 and 6 are supplementary. Both angle 4 and angle 5 are supplementary to angle 6.
Again, you will need to check the theorems you've proved so far...but you SHOULD find one that says "If two angles are supplementary to the same or to congruent angles, then those two angles are congruent."
This should be all you need to conclude that angles 4 and 5 are congruent.
