2. Shadow area = square area-1/4 circular area = 6 * 6-1/4 * 6 * 6 * 3.14.

3. The area of triangle ABC = 1/2 parallelogram =50.

Triangle ABC is an isosceles diameter triangle, the height of which is the radius of the circle and the bottom is the diameter of the circle.

The radius of a circle is 5 and the number is 2.

Shadow area = 1/4 circle area-1/2 triangle ABC area =3. 14*50/4-50/2.