What are the methods of proving triangle similarity in Geometry?

Question

I have a test tomorrow and I don't understand this topic!

Answer 1

If you are only given sides ... set up a proportion for corresponding sides.  If corresponding sides are proportional then the triangles are similar.  The hard part is to know which sides correspond to each other.  If you have tracing paper, carefully trace one of the triangles.  Then rotate the traced triangle until all the angles match up with the other triangle.  Once you find the corresponding angles, you have the corresponding sides.  Hope this helps.

Answer 2

To prove two triangles are similar it is sufficient to show two pairs of corresponding angles are congruent.