Questions in coordinate

Select	Question
	The extremities of a diagonal of a parallelogram are the points $(3,-4)$and $(-6,5)$. If third vertex is $(-2,1)$, then fourth vertex is
	(0, –1) and (0, 3) are two opposite vertices of a square. The other two vertices are
	If $A(3,\,5),B(-5,\,-4),C(7,\,10)$ are the vertices of a parallelogram, taken in the order, then the co-ordinates of the fourth vertex are
	If the point (a, a) are placed in between the lines $\|x+y\|=4$, then
	The three points (–2,2), (8,–2) and (–4, –3) are the vertices of
	The points $\left( \frac{a}{\sqrt{3}},a \right),\ \left( \frac{2a}{\sqrt{3}},\,2a \right),\ \left( \frac{a}{\sqrt{3}},\,3a \right)$are the vertices of
	The points $(a,b),\ (c,d)$and $\left( \frac{kc+la}{k+l},\,\frac{kd+lb}{k+l} \right)$ are
	The points (0, 8/3), (1, 3) and (82, 30) are the vertices of
	The points (3a, 0), (0, 3b) and (a, 2b) are
	The points $(-a,-b),\ (a,b),\ ({{a}^{2}},ab)$are