SOLUTION: Write a 2- coloumn proof. Given AB is congruent to AC Prove- measure of angle B is greater than angle of measure of angle D. The picture is of a large triangle ADB and there

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Question 117986: Write a 2- coloumn proof.
Given AB is congruent to AC
Prove- measure of angle B is greater than angle of measure of angle D.
The picture is of a large triangle ADB and there is a line going from point a to point C inbetween segmetn BD.
Answer by bucky(2189) About Me  (Show Source):
You can put this solution on YOUR website!
Here's a rough cut at it and you can clean it up to make it meet your teacher's standards:
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Given: Triangle ABD with C being a point on the line segment BD. Segment AC congruent (cong.)
to segment AB
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Prove mB (measure of angle B) > mD (measure of angle D).
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1. segment AC cong. to segment AB .... Given
2. Triangle ABC is isosceles .... Definition of isosceles ... two sides cong.
3. mB = mBCA ... In isosceles triangle measure of angles opposite cong. sides are equal
4. For Triangle ACD mBCA > mD ... exterior angle greater than either alternate interior angle
5. mB > mD ... Substitution of mB (Step 3) for its equal mBCA in Step 4
6. QED
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Hopefully this all makes sense. You may have to study it a while before it becomes apparent
what was done here. I hope that you've studied the theorems that are used above so that I
haven't used something that you are not familiar with ...
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If you have problems, re-post and some other tutor may be able to explain it better.
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