Examine the triangles in the diagram at right.  

1. Are the triangles similar? Justify your conclusion.

   Hint (a):

   There are some parallel lines in the diagram.
   Review Math Notes in Lesson 2.1.4 for help identifying the relationships between the angles lettered $a$, $b$, $c$, and $d$ below.

   

2. Solve for $x$. Show all work.

   Hint (b):

   When two triangles are similar, the ratios of corresponding sides are equal.
   You could use a proportion.

   Answer (b):

   $x=10$