Consider: A treasure is buried in your backyard. The picture below shows your backyard which contains a stump, a teepee, and a tree. The teepee is 8 feet from the stump and 18 feet from the tree. The treasure is equidistant from the teepee and the tree AND ALSO 6 feet from the stump. Locate all possible points of the buried treasure.
The red line represents the locus which is equidistant from the teepee and the tree (the perpendicular bisector of the segment). The blue circle represents the locus which is 6 feet from the stump. These two loci intersect in two locations. The treasure could be buried at either "X" location. Start digging!!
Note: The red line and blue circle could have been drawn "dotted" to indicate that they are locus locations.