Question : AB is the chord of a circle such that AB = 10 cm. If the diameter of the circle is 20 cm, then the angle subtended by the chord at the centre is?

Question : AB is the diameter of a circle with centre O. P is a point on the circle. If $\angle AOP=95^{\circ}$, then $\angle{OBP}=$

Question : AB is a chord in the minor segment of a circle with centre O. C is a point on the minor arc (between A and B ). The tangents to the circle at A and B meet at a point P. If $\angle \mathrm{ACB}=108^{\circ}$, then $\angle \mathrm{APB}$ is equal to:

Question : $\triangle \mathrm{PQR}$ is an equilateral triangle inscribed in a circle. $\mathrm{S}$ is any point on the arc $\mathrm{QR}$. Find the measure of $\angle \mathrm{PSQ}$.

Question : PQ is a tangent of a circle at T. If TR = TS where R and S are points on the circle and $\angle RST=65^{\circ}$, the $\angle PTS=?$