Exercise 7 Page 444

A midpoint is a point that is halfway between two other points. Using this fact, we can create a conditional statement. If point $M$ is the midpoint of FH, then JG=FH. Do we have any way of knowing that length JG is equal to length FH? It sure looks like it when examining the figure.

But can we prove it? No, without any markings indicating that the lengths of segments are the same, we have no way of knowing this for certain. The statement is false because we cannot prove it to be true.