BBC3 年
How to draw a regular hexagon, square and triangle
STEP 1: Using a pencil and ruler, draw a horizontal line. Set the compass to the width of the line. Place the compass at either end of the line and draw two arcs that cross in the middle.
Scientific American3 年
Here’s How to Make Flexagons—Folded Strips of Paper with Strange and Surprising Properties
Editor’s Note: Published in 1956, this article proved so popular that it served as the inspiration for Martin Gardner’s legendary Scientific American column Mathematical Games. Read more in ...