Consider the image shown below. The square is completely inscribed in the circle. The circle's radius is increasing at a rate of 0.8 cm/sec. (a) Find the area of the circle at the instant when the sides of the square are each 4 cm. (b) What is the rate of change of the circle's area at the instant the sides of the square are each 4 cm? (c) At the instant the radius of the circle is 5/2, how fast is the area of the shaded region changing with respect to time?