9. What is the value of x in the
figure shown?
104°
38°

x = 66

Step-by-step explanation:

So the angle with 104 that's the outside measure of the angle but we need to find the inside measure so first.

180 -104= 76 (so 76 is the measure to the inside angle)

Now

76 + 38 + x = 180 (collect like terms)

114 + x = 180 (minus 114 on both sides)

x = 66

Multiply the radius of the half circle by 2.

Step-by-step explanation:

You would multiply the radius of the half circle by 2.  This is because the radius is half of the diameter, or the length of a line that passes through the center of the circle.  The dotted line in the diagram is the diameter since it passes through the center of the circle and its endpoint are on the circle.