Triangle Inequality
Move the blue points to change the segment lengths.
1) Make AB = 11, AC1 = 7, BC2 = 3. Notice 7 + 3 < 11. Do the segments connect into a triangle?
2) Change BC2 = 4. Notice 7 + 4 = 11. Do the segments connect into a triangle?
3) Join points C1 and C2 to connect into a triangle. Add the 2 sides up and compare the total to side AB. What do you notice?
4) Make AB = 15, AC1 = 4, BC2 = 9. Notice 4 + 9 < 15. Do the segments connect into a triangle?
5) Change AC1 = 6. Notice 6 + 9 = 15. Do the segments connect into a triangle?
6) Join points C1 and C2 to connect into a triangle. Add the 2 sides up and compare the total to side AB. What do you notice?
7) Make a conclusion about the Triangle Inequality.