Introduction to Area of Circle

What is the area of the yellow region (rings 9 and 10) on the archery target if each ring is 4 cm wide?

What is the area of the red region (rings 7 and 8) on the archery target if each ring is 4 cm wide?

What is the area of the black region (rings 3 and 4) on the archery target if each ring is 4 cm wide?

A circle with a 12-inch diameter is folded in half and then folded in half again. What is the area of the resulting shape?

How could you estimate the area of a Hawaiian chief's feather cape?

What is the area of the shaded region in the rectangle? Express your answer in terms of $$\pi$$ .