सिद्धान्तशिरोमणि: गणिताध्याय (भास्कराचार्य - ग्रहगणित, मध्यमाधिकार व स्पष्टाधिकार सटीक)

239 (7) The seventh latitudinal triangle is D₁ S₁ B₁ where D₁ S₁ is the second segment of the Agrajyā, S₁ B₁ is the Kujyā, and D₁ B₁ is the unmandala Sanku. (8) The eighth latitudinal triangle is B₁ L₁ F₁ where B₁ L₁ is equal to the first segment of Agrajyā, L₁ F₁ is the higher segment of Agrajyā, L₁ F₁ is the higher segment of the Sama-Vritta-S'anku, and F₁B₁ is the upper segment of Taddṛti mentioned before. Comm. It was already mentioned that a latitudinal triangle is such a right-angled tri-angle constituted by the chords of the celestial sphere where the angles in the triangle are ϕ, 90 − ϕ, 90°. The side opposite to ϕ is called the Bhuja, that opposite to (90 − ϕ) is called Koti and the third Karna. Such triangles are not only eight as have been mentioned, but many more will be there as mentioned by Bhāskara. They are all formed as mentioned by him by the intersections of the diurnal paths and the celestial equator with the circles of the sphere namely horizon, prime vertical, meridian, Equatorial horizon and declination circles. These circles clearly intersect at ϕ or 90 − ϕ. The eight triangles mentioned are those whose elements will be entering computations. There is another important latitudinal triangle with which we have to deal later namely that formed by what is called Hriti, S'anku, and S'ankutala (Fig. 39). O₃K = Agrā ; O₃C = S'anku-tala ; CN = S'anku-bhuja = CK ∴ Agrā = Sankutala + Sanku-bhuja Agrā = R (H sin δ / H cos ϕ) ; S'ankutala = H cos Z tan ϕ S'anku-bhuja = (H sin z H sin a) / R (Ref. fig. 40') ∴ R (H sin δ / H cos ϕ) = H cos z tan ϕ + (H sin z H sin a) / R I