History of Hindu Mathematics: A Source Book v2.c17.s19.11

v2.c17.s19.11

The first rectangle (AA'DH) generated from m, n is $m² - n², 2mn, m² + n².$ If p, q be any two rational factors of half the base of this rectangle, that is, if pq = mn, the second rectangle (AB'CH) from these factors will be $p² - q², 2pq, p² + q².$ By judiciously juxtaposing these two rectangles, we shall obtain an isosceles trapezium of the type required (ABCD):