## Lincoln’s Top Hat

Did you know that there is a famous illusion associated with Lincoln’s “stove pipe” hat? The hat looks like it’s taller than it is wide, even when the height and width (including the brim) are the same. Let’s make a hat:

- Cut a circle with a radius of 5 1/2 inches.
- Cut a circle from the center of the first circle with a radius of 3 1/2 inches.

The smaller circle will form the tip of the hat, and what’s left of the larger circle will form the hat brim. If we had a rectangular sheet of paper of the right size, we could make the cylindrical part of the top hat.