An equilateral triangle has each side equal to a. If the co-ordinates of its vertices are (x1, y1); (x2, y2): (x3, y3) then the square of the determinant \(\begin{vmatrix} x_1 & y_1 & 1 \\\ x_2 & y_2& 1 \\\ x_3 & y_3 & 1 \end{vmatrix}\) equals:
1
None of these
2
4a2
3
3a4
4
\(\dfrac{3a^4}{4}\)