Can points A, B, C lie on one straight line if AB = 1.8 m, AC = 1.3 m, BC = 3 m?

1. Points A, B, C cannot lie on the same straight line, since three conditions characteristic of triangles are met:
a) AB <BC + AC;
b) BC <AB + AC;
c) AC <AB + BC;
2. It turns out that:
a) 1.8 <3 + 1.3;
1.8 <4.3;
b) 3 <1.8 + 1.3;
3 <3.1;
c) 1.3 <1.8 + 3;
1.3 <4.8;
3. Therefore ABC is a triangle and points A, B, C do not lie on one straight line;
4. Answer: points A, B, C cannot lie on one straight line.