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

353 followed by the ancient Hindu Astronomers to estimate the distance of the Moon, the spherical radius the hori- zontal parallax, the orbital radius pertaining to the Moon could all be deduced and the magnitudes so deduced accord with their average values in modern astronomy. The magnitudes pertaining to the Sun however, should be deemed as parameters. Verse 6. e - [(S - E) Kₘ / Ks] = 2 α where e = Earth's diameter, s = The Sun's diameter; Km = Moon's dis- tance from the Earth's centre; Ks = The Sun's distance from the Earth's centre, and α = radius of the Earth's shadow cone at the lunar orbit. Comm. In fig. 66, let CD be the radius of the Earth's shadow cone at the lunar orbit. Required to find the magnitude of CD. Triangles DEF and ESG are similar Fig. 66 Fig. 67 45