189. An altitude of a triangle is a segment that joins one of
the three vertices to a point on the line that contains the
opposite side, the intersection being perpendicular. For example,
consider the triangle whose vertices are A = (0, 0), B = (8, 0),
and C = (4, 12). (a) Find the length of the altitude from C to side
AB. What is the area of ABC? (b) Find an equation for the line that
contains the...