The Shulbasutras of Baudhayana, Apastamba, Katyayana and Manava: With Text, English Translation and Commentary c8.t11.5

c8.t11.5

The area of each wing being 63 *pañcamīs* and 6 plumages, each of half-*pañcamī*, needing an area of 3 *pañcamīs* only by analogy with the *kaṅkacit* wing, the rectangular area forming the main part of the wing to be bent should measure 60 *pañcamīs* or 6 *aratnis* × 10 *aratnis* (144 *aṅg.* × 240 *aṅg.*). *ABCD* is such a rectangle of which AB = 144 *aṅg.* and BC = 240 *aṅg.*. After bending, it assumes the form *ABECDF* so that EP = IF = 120 *aṅg.* IE clearly equals 24 *aṅg.* or 1 *aratni*. The *patras* are DK₁L₁, L₁K₂L₂ etc. From the geometry it is clear that *I*, *J*, L₅ *H* lie on the same straight line. Hence the direction (rule 13.4) that, by stretching a cord *IH*, the area *IECH* west of the southern half of the wing including the *patras* should be cut off. The area of the wing south of the *nirṇāma* line *EF* is 33 *pañcamī* and that of IECH 33 / 6 or 5½ *pañcamī*. The first line of rule 13.6 prescribes that a triangular area *EIJ* measuring a quarter brick, that is ¼ *pañcamī* is to be added. In other words, the actual area to be removed is *ECHJ* measuring (5½ - ¼) or 5¼ *pañcamī*; for two wings the area to be removed is 10½ *pañcamī*.