Learn how to evaluate the definite integral by graphing a semi circle

The video tutorial explains how to rewrite an equation to identify it as a circle equation, with a center at (0,0) and a radius of 2. It further discusses how this equation represents a semicircle, focusing on the positive form. The tutorial concludes by calculating the area of the semicircle, using the formula for the area of a circle and adjusting it for the semicircle.

How is the area of the semi-circle calculated according to the text?

What is the relationship between the area of a full circle and the area of the semi-circle discussed?