Let `C_(1)` be the circle of radius `r > 0 ` with centre at `(0,0)` and let `C_(2)` be the circle of radius `r` with centre at `(r,0)` .The length of the arc of the circle `C_(1)` that lies inside the circle `C_(2)` ,is

The length of the arc of a quadrant of a circle of radius r is

A circle of radius 2 has its centre at (2,0) and another circle of radius 1 has its centre at (5, 0).A line is tangent to the two circles at point in the first quadrant.The y-intercept of the tangent line is

The focal chords of the parabola y^(2)=16x which are tangent to the circle of radius r and centre (6, 0) are perpendicular, then the radius r of the circle is

Find an equation of the circle with centre at (0,0) and radius r.

One circle has a radius of 5 and its centre at (0,5). A second circle has a radius of 12 and its centre at (12,0). What is the length of a radius of a third circle which passes through the centre of the second circle and both the points of intersection of the first two circles.

If the length of an arc of a circle of radius r is equal to that of an arc of a circle of radius 2r, then the angle of the corresponding of the other circle. Is this statement false ? Why ?

If the line x+3y=0 is the tangent at (0,0) to the circle of radius 1, then the centre of one sum circle is