Steps of Construction :

1. Draw a line segment AB = 7 cm.
2. At A construct an angle of 600 such that AC = 5 cm.
3. Join BC to get ∆ABC.
(i) Draw angle bisector of ∠BAC, which is the required locus of the points equidistant from AB and AC.
(ii) Draw angle bisector of ∠ABC, which is the required locus of the points equidistant from BA and BC.
4. Let the two angle bisectors intersect each other in I.
5. Through I, draw ID⊥AB. With I as centre and radius = ID draw a circle which touches all the sides of the ∆ABC internally.