1. On a line, three points $A, B$, and $C$ are chosen, such that $A B=3, B C=5$. What can $A C$ be? (There are different possibilities.)

![](https://cdn.mathpix.com/cropped/2024_05_21_90703b5d5e76e3b5cd3dg-007.jpg?height=91&width=283&top_left_y=888&top_left_x=361)
$\triangle$ If point $B$ is between points $A$ and $C$, then this distance is equal to $3+5=8$. But there is another case when $B$ is outside the segment $A C$. By drawing a picture, we convince ourselves that in this case the distance is equal to $5-3=2 . \triangleleft$