Questions in coordinate

Select	Question
	A point equidistant from the points (2, 0) and (0, 2) is
	The point on y-axis equidistant from the points (3, 2) and (–1, 3) is
	If a vertex of an equilateral triangle is on origin and second vertex is (4, 0), then its third vertex is
	If the coordinates of vertices of $\Delta OAB$ are (0,0) $(\cos \alpha ,\,\sin \alpha )$ and $(-\sin \alpha ,\,\cos \alpha )$ respectively, then $O{{A}^{2}}+O{{B}^{2}}=$
	The length of altitude through A of the triangle ABC, where $A\equiv (-3,\,0);\,B\equiv (4,\,-1);\,C\equiv (5,\,2),$ is
	The distance of the point $(b\cos \theta ,\,b\sin \theta )$from origin is
	The distance of the middle point of the line joining the points $(a\sin \theta ,0)$and $(0,a\cos \theta )$from the origin is
	If the points (1,1), (–1, –1) and $(-\sqrt{3},k)$are vertices of an equilateral triangle then the value of k will be
	The points P is equidistant from A(1,3), B (–3,5) and C(5,–1). Then PA =
	The distance between the points (7, 5) and (3, 2) is equal to