Are the two triangles below similar?
http://prntscr.com/91rk7r

Yes, because the corresponding sides are proportional
No, because the corresponding sides are not proportional
Yes, because there are two pairs of congruent corresponding angles
No, because there are not two pairs of congruent corresponding angles

Question

Are the two triangles below similar?
http://prntscr.com/91rk7r

Yes, because the corresponding sides are proportional
 No, because the corresponding sides are not proportional
 Yes, because there are two pairs of congruent corresponding angles
 No, because there are not two pairs of congruent corresponding angles

leahhhmorgannn · Answer

@phi

leahhhmorgannn · Answer

@YoungStudier @just_one_last_goodbye

phi · Answer

Do you know what the 3 angles in a triangle always add up to ?

leahhhmorgannn · Answer

180 degrees?

phi · Answer

yes.  
if you are given 2 of the angles, you can find the 3rd angle
first add up the 2 angles
then do 180 - sum
to find the 3rd angle
can you do that for the two different triangles?

leahhhmorgannn · Answer

I can do that, yes.

leahhhmorgannn · Answer

So, for the bigger triangle: 95+50 = 145 
180 - 145 = 35 

35 is the other angle from the smaller triangle. 

For the smaller triangle: 35+50 = 85 
180 - 85 = 95 

85 is the other angle from the larger triangle. 

So they are similar... would it be C?

phi · Answer

yes, both triangles have the same 3 angles: 35,50, 85
so they are similar (same shape)
because "corresponding sides" are not equal they are not congruent (same size)

leahhhmorgannn · Answer

Wait, so what would the answer be then? Because that statement confused me.

phi · Answer

Yes, they are being "difficult"

but it should make sense that if you know two angles in one triangle match two angles in another triangle then you know the 3rd angles also match (because when we do the 180-sum we will get the same number for both triangles for the 3rd angle)

all of which means the triangles will be similar

leahhhmorgannn · Answer

And they're similar not because of corresponding sides, but corresponding congruent angles? 
Meaning C would be correct..?

phi · Answer

so we don't have to know all 3 angles are the same, we just need to know 2 angles are the same in both triangles.  And they say
the triangles are similar because there are two pairs of congruent corresponding angles

leahhhmorgannn · Answer

Ah, okay. Thank you for clarifying that for me.

phi · Answer

The annoying thing is they did not give us two pairs of angles that are congruent
we had to figure out the unknown angle for both triangles.  So I would have used the reason:  the triangles are similar because all 3 angles are congruent.