​ Construct Br (AB) of length 7.8 cm. From this, cut off AC of length 4.7 cm. Measure BC. ​

Question

Construct \(\over{AB}\) of length 7.8 cm. From this, cut off \(\over{AC}\) of length 4.7 cm. Measure BC.

Answer 1

(1) Draw a line land mark a point A on it.

(2) By adjusting the compasses up to 7.8 cm, draw an arc to cut 1 on B, while putting the pointer of compasses on point A. \(\over{AB}\) is the line segment of 7.8 cm.

(3) By adjusting the compasses up to 4.7 cm. draw an arc to cut 1 on C, while putting the pointer of compasses on point A. \(\over{AC}\)  is the line segment of 4.7 cm.

(4) Now, put the ruler along with this line such that 0 mark of the ruler will match with point C. On reading the position of point B, it comes to 3.1 cm, \(\over{BC} \)  is 3.1 cm