Questions in circle

Select	Question
	The locus of a point which moves such that the sum of the squares of its distances from the three vertices of a triangle is constant, is a circle whose centre is at the
	Locus of the points from which perpendicular tangent can be drawn to the circle ${{x}^{2}}+{{y}^{2}}={{a}^{2}}$ , is
	The locus of the centre of a circle which always passes through the fixed points (a, 0) and $(-a,\ 0)$ , is
	The equation to a circle whose centre lies at the point (–2, 1) and which touches the line $3x-2y-6=0$ at (4, 3), is
	The equation of a circle passing through the point (4, 5) and having the centre at (2, 2) is
	The locus of the centre of a circle which touches externally the circle ${{x}^{2}}+{{y}^{2}}-6x-6y+14=0$ and also touches the y-axis, is given by the equation
	The area of a circle whose centre is (h, k) and radius a is
	If the equation $\frac{K{{(x+1)}^{2}}}{3}+\frac{{{(y+2)}^{2}}}{4}=1$ represents a circle, then $K=$
	A circle has radius 3 units and its centre lies on the line $y=x-1$ . Then the equation of this circle if it passes through point (7, 3), is
	The equation of circle whose diameter is the line joining the points (–4, 3) and (12, –1) is