Q3. Construct AB of length 7.8 cm. From this, cut off of length 4.7 cm. Measure .
The steps of constructions:
(i) Place the zero mark of the ruler at A.
(ii) Mark a point B at a distance 7.8 cm from A.
(iii) Again, mark a point C at a distance 4.7 from A.
By measuring , we find that BC = 3.1 cm