Please help. I don't understand this

The answer is 21.33 with the three repeating forever. So it would be rounded to 21
We need to find out what's the distance between M and H, but lets first look at the triangle in the right. The lines look even and looks like it's the same length. The line for L and H is 24 and it looks very similar and even like line M and H. So, I think the best answer for this question is c) 24.
hope this helps!