Steps of Construction
(i) Draw BC = 8 cm.
(ii) Construct ∠YBC = 45°.
(iii) From ray BY, cut-off line segment BD = 3.5 cm.
(iv) Join CD.
(v) Draw perpendicular bisector of CD intersecting BY at A.
(vi) Join AC to obtain the required triangle ABC.
Justification
As A lies on the perpendicular bisector of CD. Therefore,
AD = AC
Now, BD = 3.5 cm
⇒ AB – AD = 3.5 cm
⇒ AB – AC = 3.5 cm
Hence, △ABC is the required triangle.