Steps of construction:
(We know that the locus of a point which is at a given distance from a given line is a pair of lines parallel to the given line and at a given distance from it. Hence to find the points which are 2 cm from BC, we draw two lines parallel to BC at a distance of 2 cm from it).
(We know that the locus of a point which is equidistant from two intersecting straight lines is a pair of straight lines which bisect the angles between the given lines. Hence to find the points which are equidistant from AB and AC, we draw the angle bisector of ∠BAC which intersects m and n at P and Q respectively).
Thus P and Q are the required points which are both equidistant from AB and AC and 2 cm from BC.
On measuring, we see that the distance between P and Q is 4.3 cm.