1. Draw an angle ABC equal to ∠DEF (as ∠DEF > ∠PQR), using ruler and compasses.
2. With BC as one of the arms, draw an angle SBC equal to ∠PQR such that BS is in the interior of ∠ABC as shown in Fig. 9.6. Then, ∠ABS is the require angle which is equal to ∠DEF – ∠PQR. [Note: For making ∠ABS = ∠DEF – ∠PQR, how will you draw ray BS?]