The urbanized Harappan civilization with elaborate town planning had knowledge of geometry and standardized measures. Statistical analysis of various Harappan settlements has shown that the basic unit of measurement was 17.63 mm[3]. This is taken to be one angulam and 108 angulams one dhanus. Various dimensions in the Harappan site of Dholavira are integral multiple of dhanus. Now at a different site — Kalibangan — a terracota scale was found and when the measure between the tick marks was analyzed, it was found to be 17.5 mm. This also matched the measurement found in ivory and metal scales and shell markings at other sites[1].
The angulam is approximately 1.763 cms in Harappa, 1.75 in Kalibangan, and 1.77 in Lothal. The Arthashashtra derives larger units from angulam: garhapatya dhanus is 108 angulams; 1 danda, 96 angulams.
In the Mauryan caves, it was found that the danda measured the cave perfectly. For example the Lomas Rishi cave was 6 dandas long and 3.5 dandas wide and the Sudaman cave, 10 dandas long and 3.5 dandas wide. There is some fine print here as the Arthashastra provides confusing descriptions for various measures: one hasta is either 24, 28, or 54 angulams and one danda is 96 or 192 angulams. Since 96 was used by later texts, that measure was chosen.
