The number of parallel tangents of a circle with a given tangent is

PA and PB are two tangents drawn to a circle with centre O from an external point P. If $\mathrm{\angle }APB\backslash angle\; APB$ = 30°, then $\mathrm{\angle }AOB\backslash angle\; AOB$ =

Radius of a circle with centre ‘O’ is 5 cm. P is a point at a distance of 3 cm from ‘O’. Then the number of tangents that can be drawn from point P  to circle is …………

Angle made by the minutes – hand in a clock during a period of 20 minutes is …………

From the adjacent figure, $\mathrm{\angle }APB\backslash angle\; APB$ = 40°, then $\mathrm{\angle }AOB\backslash angle\; AOB$ = …………

The length of a tangent to a circle from a point P is 12 cm and the radius of the circle is 5 cm, then the distance from point P to the centre of the circle is ………

Perimeter of a sector is ………………….. units. (l is the cured length of the arc by which the sector is formed.

Angle of a sector is 60° and radius is 14 cm, then its area is ……………….. $c{m}^{2}cm^2$ .

The longest chord in a circle is ……………

A circle can have …………….. parallel tangents.