Distance depends on the route
Distance is a familiar idea. Going from home to school, you cover some distance.
But there may be several routes from home to school. Some are longer; some are shorter.
Same start, same finish
Suppose a child has three possible routes from A to B.
| Route | Distance covered | Note |
|---|---|---|
| Route P | 320 m | The longest way round |
| Route Q | 200 m | Slightly curved |
| Route R | 240 m | Goes round the other side |
What this shows
The starting point and the finishing point are the same, yet the distance covered is not. So distance depends not only on the start and end points but also on the route taken.
Another example
Suppose a child walking from home to school goes along three legs, AB, BC and CD.
Total distance travelled
= AB + BC + CD
= 100 m + 400 m + 200 m
= 700 m
But the straight-line distance between home and school is only 500 m. That 500 m is the subject of the next page.