If we look at the smaller triangle created by the line from angle M, we can see that if we flip the smaller triangle so angles M and L would match up, the triangles are similar.
Triangle LMN is similar to Triangle LKM.
If we look at the entire triangle as a whole, we can see that is is a right triangle as well. As long as we remember to match up the angles, we can say that the triangles are similar.
