I am new to geographic information systems and i need to calculate the area of a a polygon ( a circle to be precise) that falls inside the boundaries of a region, say a state or a country. For example, in the figure below, the black outline the state in consideration and the circle is the concerned polygon. The yellow area is the area that is required. I have the concerned shapefile for the state.
I am using python. Can someone guide me about how to approach this problem?