The Shark Puzzle
The shark is sawed out as shown in the drawing and three holes bored.
To make one of the rings, draw two concentric circles—one 1/2” radius and the other 3/4” radius. First, saw out the inner circle and then the outer.
Take a piece of cord a foot long, double it and slip the loop thru the middle hole in the shark. Next, put the two ends of the cord thru the loop. Slip a ring on each end of the cord, and tie with a slip knot into the end hole in the shark.
Puzzle: Transfer a ring from one end to the other.