Steps of construction:
- Draw PQ = 3.5 cm.
- At P make an angle of 60° with the help of compass.
- At Q draw the angle of 105° with the help of protractor. Again by taking Q as centre, draw an arc of 3.5 cm which intersects the line segment at R.
- At R again draw an angle of 120°.
i.e. 360° – (60° + 105° + 75°)
= 360° – 240° = 120°
which will intersect the arm of the angle 60° at S.
Hence, PQRS is the required quadrilateral.