Question
Question: In a plane there are two families of lines y = x + r, y = – x + r. where r Î {0, 1, 2, 3, 4}. The nu...
In a plane there are two families of lines y = x + r, y = – x + r. where r Î {0, 1, 2, 3, 4}. The number of squares of diagonals of the length 2 formed by the lines is –
A
9
B
16
C
25
D
None of these
Answer
9
Explanation
Solution
Such squares are formed by alternate lines.
No. of squares =3 ×3 = 9