Question

Make a two-column proof showing statements and reasons to prove that triangle DEF is similar to triangle DGE. Can someone help?

Answer 1

What information do you need to know about two triangles to prove them similar?

Answer 2

Two corresponding angles have to be congruent.

Answer 3

I figured it out myself. My teacher said it was right.
DEF is similar to triangle DGE
Angle DEG is congruent to angle EFG - Given
Angle GDE is congruent to angle GFE - Reflexive Property of Equality
Triangle DEF is similar to triangle DGE - Angle-Angle Similarity Postulate

Answer 4

I hate to tell you, but your proof is not correct.
You can't state
"Angle GDE is congruent to angle GFE - Reflexive Property of Equality "
because you don't know that they are congruent.
Also, reflexive as a reason is used to state that something is congruent to itself.
In addition, don;t start by stating that the triangles are similar.
That is what you are trying to prove, and it comes ate the end.

Here is a correct proof:

Statements Reasons
1. m<DEG = 60; m<EFG = 60 1. Given
2. m<DEG = m<EFG 2. Substitution prop of equality
3. <DEG is congruent to <EFG 3. Def of congruent angles
4. Angle GDE is congruent to angle GDE 4. Congruence of angles is reflexive
5. Triangle DEF is similar to triangle DGE 5. Angle-Angle Similarity Postulate

Answer 5

If you interpret the angle markings at the two 60-deg angles to mean they are congruent as given information, then you can skip my first two steps and start with statement 3, and the reason will be Given, as you have in your own proof.

Answer 6

Well I guess I'm not that smart, not with math anyway :( I did the best that I knew how to complete the problem by myself. I posted the question 8 days ago. Theses type of problems really confuse me! My teacher gave me credit for my effort, so I'm happy with that! Thank you for your explanation!

Answer 7

You're welcome.