Given $\overline{AB}$ of length 7.3 cm and $\overline{CD}$ of length 3.4 cm, construct a line segment $\overline{XY}$ such that the length of $\overline{XY}$ is equal to the difference between the lengths of $\overline{AB}$ and $\overline{CD}$. Verify by measurement.

Step I : Construct $\overline{AB}$ = 7.3 cm and $\overline{CD}$ = 3.4 cm.

Step II: Take a point $X$ on the given line $l$.
Step III: Construct $\overline{XP}$ such that $\overline{XP}$ = $\overline{AB}$ = 7.3 cm.
Step IV: Construct $\overline{YP}$= $\overline{CD}$ = 3.4 cm such that $\overline{XY}=\overline{AB}-\overline{CD}$ .
Verification: On measuring, we observe that $\overline{XY}=3.9 cm$

 $\begin{array}{c}\overline{XY}=\overline{AB}-\overline{CD}\\ \overline{XY}=7.3-3.4\\ \overline{XY}=3.9 cm\end{array}$ 
Thus, $\overline{XY}=\overline{AB}-\overline{CD}$.