2 discovering with hands-on method
- 2. 1. On a piece of plain white paper, draw a
triangle and cut it out.
- 4. 3. Now tear off each corner of the triangle and
rearrange the 3 “angles” so that their vertices
meet at one point with no overlap.
- 5. 3. Now tear off each corner of the triangle and
rearrange the 3 “angles” so that their vertices
meet at one point with no overlap.
- 6. 4. What does this tell you about sum of the
angles in the triangle?