Q1 of 23 Page 283

Let us draw the mean proportional of the following line segment and let us measure the values of the mean proportionals in each case with help of a scale:

5cm., 2.5cm

Construction steps:


1. Draw a line segment AX with length greater than (5 + 2.5 = 7.5 cm).



2. From A, mark a point B on AX such that AB = 5 cm and from B mark a point C such that BC = 2.5 cm



3. Draw the perpendicular bisector of AC, such that it cuts AC at O.



4. Taking OA = OC as radius and O as center draw a semicircle.



5. Draw BD AC such that, point D lies on the semicircle and



Here, BD is the mean proportional of AB and BC, and By construction AB = 5 cm and BC = 2.5 cm.


With the help of scale, we measure BD = 3.5 cm [Appx]


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