Ex 11.2, 3
Construct a triangle PQR in which QR = 6 cm, ∠Q = 60° and PR − PQ = 2 cm.
Given that, In ∆PQR, QR = 6 cm, ∠Q = 60° and PR − PQ = 2 cm.
Steps of Construction
 Draw base QR = 6 cm and at point B make a ∠ XQR = ∠ Q = 60°

Cut a line segment QD equal to PR – PQ from ray BX

Join DR. Draw perpendicular bisector
AB of line DR. 
Let AB intersect QX a point P.
Join PR.
∴ Δ PQR is the required triangle