Easy square trick

Slogan for square

X² = B² ± 2DB + D²

Where ,

X = a number of which we have to find out square

B = a nearest number of which square can be count easily

D = a different between X & B

± = if B is big then ( - )and if B is small then ( + )

Example :

Find out (43)²

X² = B² ± 2DB + D²

Here,

X = 43
B = 45
D = 2
± = -

(43)² = (45)² - ( 2 * 2) (45) + (2)²
  = 2025 - 4 * 45 + 4
  = 2025 - 180 + 4
(43)² = 1849

Now suppose B is 40 then

D = 3
± = +

(43)² =(40)² + (2 * 3 ) (40) + (3)²
  = 1600 + 6 * 40 + 9

  = 1600 + 240 + 9

(43)² = 1849