Question

I need help on a proof

Answer 1

@Directrix @uri @iGreen @SolomonZelman

Answer 2

@chosenmatt

Answer 3

@amistre64

Answer 4

you havent actually posted what you need to prove.

Answer 5

oh crap

Answer 6

Make a two-column proof showing statements and reasons to prove that triangle ABD is similar to triangle ACB.

Answer 7

one of my many shortcomings ... 2 column geometry proofs. i never really got the hang of them. srry.

Answer 8

Oh okay, thanks anyway

Answer 9

good luck :) there are bound to be others on here that are genuises at them ;)

Answer 10

@Wriddler what is your question please?

Answer 11

Make a two-column proof showing statements and reasons to prove that triangle ABD is similar to triangle ACB.

Answer 12

is the edge BD a particular edge?

Answer 13

@Wriddler - do you know what makes two triangles similar?

Answer 14

triangles ABC and ABD has all three angles equal neatly, because they have two angles of 45, and angle whose vertex is A is common. So since three internal angles of a triangle have to sum up to 180, the third angle must be equal for both triangles

Answer 15

oops sorry ...have all three....

Answer 16

The figure is above if you didnt see

Answer 17

@Wriddler do you agree?

Answer 18

Yes I agree

Answer 19

the two triangles, namely ABC and ABD, have two couple of angle neatly equals, so they are similar by the first criterion of similutude

Answer 20

oops ....have two couples of angles....

Answer 21

So how would the entire proof look in this case?

Answer 22

I know to start with Angle B in triangle ABD is congruent to angle C
Given but from there?

Answer 23

angle whose vertex is A is congruent for both triangles, because it is in common

Answer 24

so our triangles: ABC, and ABD havetwo couple of angles congruent neatly, and by first criterion of similitude they are similar triangle

Answer 25

two couples of angles congruent neatly each other

Answer 26

Could I also say that they are similar by AA theorem?

Answer 27

AA similarity postulate*

Answer 28

Sorry I don't know the AA theorem, our triangles are similar because each of triangle has two internals angles which are congruent neatly to the two internal angles of the other triangle, namely the first criterion of similitude between triangles

Answer 29

I think your AA theorem is my first criterion of similitude

Answer 30

Angle-Angle (AA) Similarity Postulate: If two triangles have congruent angles, the triangles are similar. So since there are two congruent angles I could put this in my proof correct?

Answer 31

that's right! there are two congruent angles for each triangle

Answer 32

Okay awesome, Thank you!

Answer 33

thank you!