-Draw a diagram showing the given lines and points.
-Read carefully to determine the needed condition(s).
-Locate one point that satisfies the needed condition and plot it on your diagram.
-Locate several additional points that satisfy the condition and plot them as well.
-Plot enough points so that a pattern (a shape, a path) is starting to appear.
-Through these plotted points draw a dotted line to indicate the locus (or path) of the points.
-Describe in words the geometric path that appears to be the locus.
-If TWO conditions exist in your problem (a compound locus), repeat steps as above for the second condition ON THE SAME DIAGRAM.
-Count the number of points where the two loci intersect.
(Where do the dotted lines cross?)
And, the below diagrams showed the types of locus theorem:
LOCUS THEOREM 1
-The locus of points at a fixed distance, d, from point P is a circle with the given point P as its center and d as its radius.
LOCUS THEOREM 2
-The locus of points at a fixed distance, d, from a line, l, is a pair of parallel lines d distance from l and on either side of l.
LOCUS THEOREM 3
-The locus of points equidistant from two points, P and Q, is the perpendicular bisector of the line segment determined by the two points.
LOCUS THEOREM 4
-The locus of points equidistant from two parallel lines, l1 and l2 , is a line parallel to both l1 and l2 and midway between them.
LOCUS THEOREM 5
-The locus of points equidistant from two intersecting lines, l1 and l2, is a pair of bisectors that bisect the angles formed by l1 and l2 .