The Shulbasutras of Baudhayana, Apastamba, Katyayana and Manava: With Text, English Translation and Commentary c8.t25.9

c8.t25.9

The one-twelfth brick, *abc*, for the first layer has each of its two equal sides one-twelfth of *AB* or *AC* and the base one-twelfth of *BC* The half bricks are obtained by dividing *abc* vertically by *af*, and the quarter bricks by joining the mid-points *g*, *h*, *f* of the three sides (Fig. 13(b)). Sundararāja prescribes the use of one-ninth bricks by trisecting the three sides of the one-twelfth brick and joining them, as shown in Fig. 13 (c). For the second layer, one-thirteenth and their sub-divisions are used. The dimensions are: B₁ — one-twelfth (*dvādaśī*) isosceles triangular: side — 43 *aṅg* 10 *ti*, base — 38 *aṅg* 25 *ti* (Karavinda) ; B₂ — half of one-twelfth—43 *aṅg* 10 *ti*; 38 *aṅg* 25 *ti*; 19 *aṅg* 12½ *ti*.; B'₁ — one-thirteenth (*trayodaśī*) isosceles triangular: side—39 *aṅg* 33 *ti* (= 40 *aṅg*—1 *ti*) ; base—35 *aṅg* 25 *ti.* ; B'₂ = half of one-thirteenth—39 *aṅg* 33 *ti*; 35 *aṅg*. 25 *ti*; 17 *aṅg* 29½ *ti*. All these values agree with Karavinda's. Dimensions of quarter and one-ninth bricks are not given.