58. If you wish to turn a square into a circle draw half of the cord stretched in the diagonal from the centre towards the prāchī line. Describe the circle together with the third part of that piece of the cord which stands over.
Āryabhata's gaņita—(Circa. A.D. 520).
6. The area of a triangle is the product of the perpendicular common to the two halves and half the base. Half the product of this and the height is the solid with six edges.
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10. Add four to one hundred, multiply by eight and add again sixty-two thousand. The result is the approximate value of the circumference when the diameter is twenty thousand.
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13. The circle is produced by a rotation; the triangle and the quadrilateral are determined by their hypotenuses; the horizontal by water and the vertical by the plumb line.
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29. The sum of a certain number of terms diminished by each term in succession added to the whole and divided by the number of terms less one gives the value of the whole.
Brahmagupta—(Born A.D. 598).
1. He who distinctly knows addition and the rest of the twenty operations and the eight processes including measurement by shadows is a mathematician.
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14. The principal multiplied by its time and divided by the interest, and the quotient being multiplied by the factor less one is the time. The sum of principal and interest divided by unity added to the interest on unity is the principal.
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