You should recognize g as the equation of a semicircle, centered at the origin with radius 6.
View the eTool. The height of the triangle is 5 and the hypotenuse is 6. Use these lengths to calculate the measure of the central angle.
Use the eTool below for parts (a) - (c).
Click the link at right for the full version of the eTool: Calc 1-54 HW eTool