Construct triangle A Bc in which bc=8cm angle b=45dgry and ab-bc =3.5cm
Take base bc 8 cm draW 45' on point b and extend this line. cut ab-ac i.e. 3.5 cm and join it to point c & name it point x . Make perpendicular bisector of xc . Where the bisector joins 45' line. Name that point a and join it to c . ABC is req. Triangle