Answer:
The error in this flowchart is:
4. Point L is equidistant from points J and K; Definition of Equidistant.
The flowchart incorrectly states that point L is equidistant from points J and K. However, this is not true. Point L is the midpoint of segment JK, as stated in the correct definition of a perpendicular bisector. The correct statement should be that segment JL is congruent to segment KL, not that point L is equidistant from points J and K.
This error occurs because the flowchart incorrectly connects the congruence of the triangles JNL and KNL (SAS Postulate) to the statement that segment JL is congruent to segment KL. The correct flow should connect the congruence of the triangles to the fact that segment JN is congruent to segment KN (which follows from the definition of a perpendicular bisector). From the congruence of the triangles, we can then conclude that segment JL is congruent to segment KL using the Corresponding Parts of Congruent Triangles are Congruent (CPCTC) postulate.
In summary, the error in the flowchart is that it incorrectly concludes that point L is equidistant from points J and K, when in fact, point L is the midpoint of segment JK.