The Shulbasutras of Baudhayana, Apastamba, Katyayana and Manava: With Text, English Translation and Commentary c8.t18.43

c8.t18.43

The method of enlargement of a square of side *a* by an increment of length *x* is obtained by (a + x)² = a² + 2ax + x², where ABCD is a square of side AB = a, and BE = DH = increment *x* (Fig. 4). For obtaining (a + x)², two rectangles of area *ax* are joined at two sides of the original square and a small square of side *x* is added at the corner. This formula is given by Euclid II.4.