# Similar Triangle Tricks

If two triangles have a side that are of equal length, and also have an equal angle, are those triangles similar?

I know that two triangles are similar if: there are two corresponding congruent angles (AA), if the corresponding sides are of equal proportion (SSS), or if they have two corresponding sides of equal proportion and a corresponding congruent angle in between (SAS)

However, while reading my physics textbook, they throw around the similar triangle argument everywhere. In some instances it looks as if they are claiming that two triangles are similar if you can find an equal angle and an equal side length.

Are there any tricks you know of for determining similar triangles besides the AA, SSS, and SAS?

No, not necessarily, even if the equal angles "touch", as you say, the respective equal sides, Say take two triangles each with base $1$, one of them with angles $30^o$ at "the left" and say $50^o$ "at the right (and $100^o$ at "the top"), and for the other triangle $30^o$ at "the left" and say $40^o$ "at the right (and $110^o$ at "the top").