Construct a plain scale:

The distance between Indore and Bhopal is 180 kilometer. It is represented on the map via 9 centimeter. Construct a plain scale for such map, illustrating minimum 1 kilometer distance and long sufficient to measure 360 kilometer.

Solution

 RF of the scale as = 9 centimeter/ (180 × 1000 × 100) centimeter

                              =    1/2 × 10 ⁶

 Length of the scale = RF × Maximum length to be measured

 (1/2 × 10⁶)* × 360 × 10⁵ centimeter

= 18 centimeter

 So now, the minimum distance that this scale must be capable to read is specified as 1 kilometer and like this is a plain scale, the major divisions will be of 10 km all and sub-divisions of 1 kilometer all.

(a)   Draw a line 18 centimeter long and divide it into 36 equivalent divisions. All division will present as10 kilometre.

(b)   Draw another line parallel to, and 5millimeter above, such line of the similar length.

RF =1/2 × 10⁶

(c)    Finish the rectangle and draw vertical lines from all division to join both horizontal lines.

(d)   Sub-divide the first division into ten equivalent parts.

(e)   Write down zero or "0" at the first division and as 10, 20, 30 ... 350 on the subsequent division on the right-hand side.

(f) Scratch 1 2 3 ... 10 on sub-divisions however starting from zero and proceeding on the left-hand side.

(g) Write down RF just above the scale.