There is a small circle in the big circle. A chord of the big circle is close to the small circle and parallel to the line connecting the centers of the two circles. The chord length is 16. Calculate the shadow area (big circle small circle)

There is a small circle in the big circle. A chord of the big circle is close to the small circle and parallel to the line connecting the centers of the two circles. The chord length is 16. Calculate the shadow area (big circle small circle)

Move the small circle to the center of the circle to coincide with the center of the big circle,
According to the vertical diameter theorem, R & # 178; - R & # 178; = 8 & # 178;
S shadow = π R & # 178; - π R & # 178; = 64 π

The diameter of the big circle is 8m, and the radius of the small circle is 2m. Calculate the area of the shadow between the big circle and the small circle. (pi = 3.14, keep two significant numbers)

37.68

As shown in the figure, the radius of the big circle is 5cm, and the shadow part accounts for one tenth of the area of the big circle and one fourth of the area of the small circle. What is the area of the small circle?

The area of the great circle is 3.14 × 5 × 5 = 78.5 square centimeters
So the shadow is 78.5 × 1 / 10 = 7.85 square centimeters
So the area of the small circle is 7.85 △ 1 / 4 = 31.4 square centimeters