Lesson 9 of 11
The big picture
Show on a big screenEvery flattened box on the table now folds back into a box.
| Idea | How it goes |
|---|---|
| Faces, corners, edges | A cube has 6, 8 and 12. |
| A net | A flat plan that folds up. One flat piece per face. |
| Nets that fail | Of 35 ways to join six squares, 11 close into a cube. |
| Views | Front, top and side. A cone gives a triangle and a circle. |
| Prisms and pyramids | Prism on n sides: n + 2, 2n, 3n. Pyramid: n + 1, n + 1, 2n. |
| Sierpinski triangle | Take out the middle. Triangles left: 3 times more each step. |
| Koch snowflake | Sides: 4 times more each step. Outline: 4/3 times longer. |
| Sierpinski carpet | Take out the middle ninth. Squares left: 8 times more each step. |
Part II, Chapter 4 is Exploring Some Geometric Themes. Read it next and find these ideas in it.