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

552 89. Tithi-kṣaya : Since a Tithi falls short of a Sāvanāha or civil day, in course of time, it so happens, that a tithi begins after sun-rise and does not last upto the next sun-rise. Such a tithi is said to be lost and goes by the name Tithi kṣaya. One such tithi kṣaya occurs out of 64 tithis approximately or eleven out of 703 more approximately. 90. Tretāyuga : Thrice the period of a Kaliyuga. 91. Trijyā : The Hindu sine of three Rasis or 90° equal to R or 3438 units. 92. Udaya : Rising or heliacal rising. 93. Unmaṇḍala or : The great circle through the celestial pole Udvṛtta and the east point. 94. Unmaṇḍala : The Hindu cosine of the altitude of a Śaṅku celestial body situated on the unmaṇḍala. 95. Upavṛtta : A small circle parallel to the prime vertical through a star or a planet. 96. Vighaṭi or Vināḍi: One sixtieth of a ghaṭī. 97. Vikṣepa or śara : Celestial latitude. or Viśikha 98. Viṣuvatbindu : Equinoctial point. 99. Viṣuvat-chāyā : The shadow cast by the gnomon when the Sun is at the point of intersection of the celestial equator and the meridian on an equinoctial day. 100. Viṣuvat-Vṛtta : Celestial equator. 101. Vṛtta or Maṇḍala: A circle.