Use the diagram of $⊙C$ at right to answer the questions below. Each part is a separate problem. 

1. If $x = 28°$, what is $m\overarc { A D }$?

   Hint (a):

   Recall that the measure of each inscribed angle is half the arc it intercepts.

   More Help (a):

   What is the sum of interior angles for triangles?

2. If $AD = 5$ and $BD = 5\sqrt { 3 }$, what is the area of $⊙C$?

   Hint (b):

   Knowing that $m∠D$ is $90°$, use the Pythagorean Theorem to solve for the $AB$.

   More Help (b):

   Then from there, substitute the information you found in the equation for the area of a circle.

   Answer (b):

   $25π$ units^{$^2$}

3. If the radius of $⊙C$ is $8$ and if $m\overarc { B D }= 100°$ , what is $BD$?

   Hint (c):

   Recall your trigonometric ratios.