Answer:

To answer the questions, it is important to know that an inscribed angle is one that has its vertex on the circle and its sides intersecting the circle at two points. In this case, Angle OGA is an inscribed angle in Circle L.

The measurement of Arc OA can be found by subtracting the measure of Arc AG from the measure of the entire circle, which is 360 degrees. Therefore, the measurement of Arc OA is 360 - 160 = <<360-160=200>>200 degrees.

The measurement of Arc OG can be found by subtracting the measure of Angle OGA from the measure of Arc OA. Since the measure of Angle OGA is 75 degrees, the measure of Arc OG is 200 - 75 = <<200-75=125>>125 degrees.

The measure of Angle GOA can be found by subtracting the measure of Angle OGA from 180 degrees, which is the total measure of an inscribed angle that is formed by two arcs of a circle. Therefore, the measure of Angle GOA is 180 - 75 = <<180-75=105>>105 degrees.

The measure of Angle GAO is simply equal to the measure of Angle GOA, since the two angles are part of the same triangle and therefore have the same measure. Therefore, the measure of Angle GAO is also 105 degrees.