Answer:
<h2>x = -0.5</h2>
Step-by-step explanation:

The sum of the interior angles of a triangle is 180. Add the three measures given and if you get 180 then those can be the interior angles of a triangle.
Answer:
DE/AB= DC/AC , 12/AB= 6/11 , AB= 12×11/6=2×11=22 , Sory i can't explain , i bad know english language. or so ABC~CDE because DE||AB=> DE/AB=DC/AC