One-half of the whole arc of a circle is called a . (semicircle, quarter circle)

‘O’ is the centre of the circle. The area of the shaded region in the given figure is $126 c{m}^2 , \overline{PQ} = \overline{PR}$ then the diameter $QR$ is:

In the given figure $TP$ and $TQ$ are two tangents to the circle with centre $O$, touching at $A$ and $C$ respectively. If $\angle BCQ=55°$ and $\angle BAP=60°$, find$\angle AOC.$

In the given figure, three circles with centres $A, B, C$ respectively touch each other externally. If $AB=5cm, BC=7cm$ and $CA=6cm$, then the radius of the circle with centre $A$ is

In the given figure, $ABCDE$ is a pentagon inscribed in a circle such that $AC$ is a diameter and side $BC\parallel AE$. If $\angle BAC=50°$, find giving reason $\angle EDC$.

From the figure of $\odot \left(O,r\right)$ match the following. The correct option is _____

Match

$\left(1\right) \overline{AC}\cup \stackrel{⏜}{ABC}$                 $\left(a\right)2r$

$\left(2\right)\overline{OA}$ length                      $\left(b\right)r$

$\left(3\right)\overline{AC}$ length                      $\left(c\right)\mathrm{\pi r}+2\mathrm{r}$

Chords $AB$ and $CD$ are intersecting at $P$. $AB=10$ centimetres, $PB=4$ centimetres and $PD=3$ centimetres. What is the length of $PA$?

In the figure given below $O$ is the centre of the circle. If the $QR=OP$ and angle $\angle ORP=20°$. Find the value of $x$ giving reasons.

In the given figure, $ABCDE$ is a pentagon inscribed in a circle such that $AC$ is a diameter and side $BC\parallel AE$. If $\angle BAC=50°$, find giving reason

$\angle BEC$

In the figure given below, $O$ is the centre of the circle and $AB$ is a diameter. If $AC=BD$ and $\angle AOC=72°$. Find $\angle ABD$ in degrees.

In the figure given below, $O$ is the centre of the circle and $AB$ is a diameter. If $AC=BD$ and $\angle AOC=72°$. Find $\angle ABC$.

In the figure given below, $O$ is the centre of the circle and $AB$ is a diameter. If $AC=BD$ and $\angle AOC=72°$. Find $\angle BAD$.

In the figure, $a, b, c$ are the sides of a right triangle where $c$ is the hypotenuse. Prove that the radius $r$ of the circle which touches the sides of the triangle is given by $r=\frac{a+b+c}{2}$.