Construct a triangle ABC in which base BC = 5.7 cm, ∠B = 30° and difference between other two sides is 3 cm.

                                              
Steps of Construction
(i) Draw BC = 5.7 cm.
(ii) Construct ∠ CBX = 30°. 
(iii) With B as centre and radius 3 cm cut an arc on the ray BX at P.
(iv) Join PC.
(v) Draw the perpendicular bisector of PC, meeting BP produced at A.
(vi) Join AC.
Then, ABC is the required triangle.