Comparison of line segments using divider

Which method is better for comparison of line segments : observation or divider ?

Comparison of angles by using trace paper.

To find a point P on the line segment AB = 6 cm, such that (AP)/(AB) = (2)/(5) , in which ratio the line segment AB is divided.

PQ is a line segment of length 6.4 cm. Geometrically obtain point R on PQ such that (QR)/(PQ) = (5)/(8) . In which ratio the line segment PQ is divided ?

Properties of Line segment: (i) line segment length (ii) Congruent line segment length (iii) line segment construction

To divide a line segment in a given ratio.