அஷ்டகவர்க்க திரிகோண சோதனை - பிருஹத் பராசர ஹோர சாஸ்திரம்

1-2. The sage said. O Brahmin! After preparing the AshtakaVarg of all the Grahas, including Lagn, Trikon Shodhana has to be done for each Rasi. A Trikon is made of three Rasis equidistant from each other. Thus Mesh, Simh and Dhanu, Vrishabh, Kanya and Makar, Mithun, Tul and Kumbh, Kark, Vrischik and Meen form the Trikonas of the Rasis.

3-5. The Trikon Shodhana (rectification) should be done by writing the Rekhas in the AshtakaVargas of Surya etc. under the Rasis Mesh etc. Amongst the Trikon Rasis the Rasi, which has lesser number of Rekhas, should be allotted Rekhas, arrived at by deducting its number of Rekhas from the greater number of Rekhas of the three Trikon Rasis. No Trikon Shodhana is necessary, if any of the Trikon Rasis has no Rekha. Shodhana should be done, if all the three of them have equal number of Rekhas, that is a zero should be written against all of them. Thereafter Ekadhipatya Shodhana should be done in the same manner, described later. (For Shodhana of the AshtakaVarg of a Grah the first thing to be done is to see, in which Rasi the Grah is posited. Beginning from that Rasi, the names of the 12 Rasis should be written and then the names of the Grahas, posited in them, should be mentioned against them. Thereafter the Rekhas, gained by that Rasi, should be written below them and the number, achieved after Shodhana, below it)