Collinear Points Three or more points are
collinear when they all lie on the same line. Use the
steps following to determine whether the set of points
$\{A(2,3), B(2,6), C(6,3)\}$ and the set of points $\{A(8,3),$
$B(5,2), C(2,1) \}$ are collinear.
(a) For each set of points, use the Distance Formula to
find the distances from $A$ to $B,$ from $B$ to $C,$ and
from $A$ to $C .$ What relationship exists among these
distances for each set of points?
(b) Plot each set of points in the Cartesian plane. Do all
the points of either set appear to lie on the same
line?
(c) Compare your conclusions from part (a) with the
conclusions you made from the graphs in part (b).
Make a general statement about how to use the
Distance Formula to determine collinearity.