`x ^(2) + y^(2) + 8x -20y =28`
What is the diameter of the circle given by the equation above ?

x^(2)+y^(2)-6x+8y=56 What is the area of a circle whose equation is given above?

If the lines x + y =6 and x + 2y =4 be diameters of the circel whose diameter is 20, then the equation of the circle is

If the lines x + y =6 and x + 2y =4 be diameters of the circel whose diameter is 20, then the equation of the circle is

If a circle is concentric with the circle x^(2) + y^(2) = 8 and its diameter is 4 units , which of the following will be the equation of the circle ?

A circle is drawn on the chord of a circle x^(2) + y^(2) =a^(2) as diameter. The chord lies on the line x+y = a . What is the equation of the circle ?

x ^(2) + 6x + y^(2) -8y =171 The equation of a circle in the xy-plane is shown above. What is the positive difference between the x-and y-coordinates of the center of the circle ?

(i) Find the equation of a circle , which is concentric with the circle x^(2) + y^(2) - 6x + 12y + 15 = 0 and of double its radius. (ii) Find the equation of a circle , which is concentric with the circle x^(2) + y^(2) - 2x - 4y + 1 = 0 and whose radius is 5. (iii) Find the equation of the cricle concentric with x^(2) + y^(2) - 4x - 6y - 3 = 0 and which touches the y-axis. (iv) find the equation of a circle passing through the centre of the circle x^(2) + y^(2) + 8x + 10y - 7 = 0 and concentric with the circle 2x^(2) + 2y^(2) - 8x - 12y - 9 = 0 . (v) Find the equation of the circle concentric with the circle x^(2) + y^(2) + 4x - 8y - 6 = 0 and having radius double of its radius.

Find the circle and radius of the circle given by the equation 2x^(2)+2y^(2)+3x+4y+(9)/(8)=0

Equation of the circle concentric with the circle x^(2) + y^(2) + 8x + 10 y - 7 = 0 , and passing through the centre of the circle x^(2) + y^(2) - 4x - 6y = 0 ,is