Folding Postage Stamps - Annie Fetter Geometry, difficulty level 2. Fold a block of eight postage stamps, as indicated, along the perforations and without tearing, so as to form a single pile with the stamps numbered consecutively from top to bottom. The Hexagonal Cross Section of a Cube - Annie Fetter Geometry, difficulty level 3. Explain how to get a hexagonal cross section of a cube. You're given two spheres with centers 14 cm apart.
Unit cubes form a larger cube.
Some faces of the larger cube are painted. Learning About GPS - Annie Fetter Geometry, difficulty level 4. The Length of a Belt - Annie Fetter Geometry, difficulty level 3. The diameters of two wheels are 18 cm and 12 cm and their centers are 30 cm apart. A belt goes around them and crosses 18 cm from the center of the big wheel.