CLASS-8
ARC OF A CIRCLE
Arc of a circle –
A continuous part of a circle would be considered as an arc of the circle. In the figure, AB is considered as an arc of the circle. In the figure, AB is an arc. The symbol for an ark is ⌢. Thus AB denotes the arc AB.
Circumstances of a circle –
The length of the boundary of any circle will be called or considered as the circumference of the circle.
Semi-Circle –
A semicircle is half a circle formed when a circle is cut along a diameter. In the figure, arcs PRQ and PSQ are two semicircles.
Minor & Major Arcs of a Circle –
When P & Q are two points on a circle not at the ends of a diameter, the smaller part of the circle from P & Q is called the minor arc and the largest part from P & Q is called the major arc.
The Angle Subtended by an Arc –
In the figure, A is a point on a circle that has its centre at O. PQ is an arc of the circle. Then ∠PAQ is the angle subtended by PQ at point A of the circle. the ∠PAQ is the angle subtended by PQ at the centre ‘O’ of the circle.
Central Angle –
The angle subtended by any arc of a circle at the centre of the circle will be called or considered as a central angle on the arc. In the figure, ∠POQ, ∠QOR, and ∠POR are all central angles.