Since the angles in triangle ACM indicate that it is a 30-60-90 triangle, we know that the other two sides of triangle ACM are 20 and 10 (30-60-90 triangles have a very specific side coefficient). This means that the sides of this triangle have side lengths 40, 10, and [tex]20\sqrt{3}[/tex]. Adding these together you get 50+[tex]20\sqrt{3}[/tex]. Hope this helps!
