Surya Siddhanta
ग्राह्यग्राहकयोगार्धसम्मितेन द्वितीयकम्। मण्डलम् तत् समासाख्यम् ग्राह्यार्धेन तृतीयकम्॥
(On the same centre,) describe a second circle named the samása with the radius equal to half the sum of the diameters of that which is to be covered and that which is the coveror, and a third circle with the radius equal to the semi-diameter of that which is to be covered.
english translation
grAhyagrAhakayogArdhasammitena dvitIyakam। maNDalam tat samAsAkhyam grAhyArdhena tRtIyakam॥
hk transliteration by Sanscript