A ) ( x - 3 )( x + 1 ) [ not perfect ]
B ) ( x + 5 - √5 )( x + 5 + √5 ) [ n p ]
C ) ( x + 2 + 2√2 )( x + 2 - 2√2 ) [n p ]
D ) ( x - 6 )( x - 6 ) = ( x - 6 )^2 [ perfect ]
Thus the correct answer is option D .
Length of 1 = 300 = 3 *10^2 nanometers
= 3*10^2/1*10^9 m
= 3*10^(2-9)
= 3*10^-7m
The answer is A because there are only acute angles
