Q: Find the distance between (1,2) and (4,6). Also check if (0,0), (3,4), (6,8) are collinear via distances. Δx = 3, Δy = 4: d = √(9+16) = 5. Distances: 5, 5, 10. 5 + 5 = 10, so collinear (middle point between).