First, draw a square. The side length of the square is the diameter. Draw four semicircles in the square.

Second, draw a circle first, then draw two vertical diameters, and then draw a semicircle clockwise with the radius of the big circle as the diameter.

Third, draw a circle first, then a diameter (pencil), then draw two semicircles clockwise with the two radii of the big circle as the diameter, and erase the original diameter.

Fourth, draw a big circle first, then draw two vertical diameters on the circle (pencil, the back should be erased), then draw a semicircle clockwise with these four radii as the diameters, and erase the starting diameter.

These boxes are painted and the bottom is colored.