The diameter of the big circle is 8 cm, and the area of the small circle should be calculated I don't know the picture. There is a biggest square in the middle of a big garden. There is a biggest Garden (small circle) in that square. How to calculate

The diameter of the big circle is 8 cm, and the area of the small circle should be calculated I don't know the picture. There is a biggest square in the middle of a big garden. There is a biggest Garden (small circle) in that square. How to calculate

The center of the small circle, the vertex of the square and the tangent point of the circle and the square form a right triangle
Radius of small circle r = radius of large circle R 2 / 2 times of radical
R = 2 times the root sign 2
The area is 8pi

Calculate the area radius of each circle to be 3 cm and the diameter to be 8 cm

Question 1: the square of 3 times 3.14
Question 2: 8 divided by 2 = 4 (radius), the square of 4 times 3.14
You can understand that

The area of a semicircle is 9 π. Find its diameter

If the area of a semicircle is 9 π, then the area of a full circle is 18 π
The radius of the full circle is (root sign 18), that is, 3 √ 2 (root sign 2)
Its diameter is 6 √ 2