Points are marked on the straight line: A, B, C = AB = 12cm, BC = 6cm, find AC (consider all cases).

1. Build a segment. Let’s designate point A (She is on the left), We put point B (On the right), and in the middle, closer to point B, we put point C. Let’s designate with an arc that AB-12 cm, BC-6 cm.
AC = 12-6 = 6 cm. (AC)
2. Build a segment, denote the point A (Left), C (Left) and B (Closer to C)
12 + 6 = 18 cm.