If the lines 2x - 4y -9= 0 and 6x - 12y + 7 = 0 are tangents to a circle, then find the radius of the circle.

If the lines 3x-4y+4=0 and 6x-8y-7=0 are tangents to a circle, then find the radius of the circle.

If the lines 12x + 5y + 16 = 0 and 12 x+ 5y - 10 = 0 are tangent to a circle then the radius is :

If the lines 3x - 4y- 7 = 0 and 2x - 3y- 5 = 0 are two diameters of a circle of area 49 pi square units, then the equation of the circle is :

If the lines 3x-4y-7=0 and 2x-3y-5=0 are two diameters of a circle of area 49pi square units, the equation of the circle is

The lines 2x-3y=5 and 3x-4y=7 are the diameters of a circle of area 154 sq. units. Then the equation of the circle is a. x^(2)+y^(2)+2x-2y-62=0 b. x^(2)+y^(2)+2x-2y-47=0 c. x^(2)+y^(2)-2x+2y-62=0 d. x^(2)+y^(2)-2x+2y-47=0

If lines 5x + 12y-10 = 0 and 5x- 12y - 40 =0 touch a circle C_1 of diameter 6, and if the centre of C_1 lies in the first quadrant, find the equation of a circle C_2 , which is concentric with C_1 and cuts intercept of length 8 on these lines.

The radius of the circle having the lines 3x - 4y + 4 = 0 and 6x - 8y - 7 = 0 as tangents is :

If the line x+2b y+7=0 is a diameter of the circle x^2+y^2-6x+2y=0 , then find the value of b .

If the circle x^2+y^2+2x+3y+1=0 cuts x^2+y^2+4x+3y+2=0 at A and B , then find the equation of the circle on A B as diameter.

If the straight line ax + by = 2 ; a, b!=0 , touches the circle x^2 +y^2-2x = 3 and is normal to the circle x^2 + y^2-4y = 6 , then the values of 'a' and 'b' are ?