Circle: Diameter, Radius, and Chord
A circle is formed by points that are same distance from a fixed point called the centre of the circle.
The centre of a circle is a point: A circle is named after its centre. If centre of a circle is point O, the circle would be named circle O or the circle with centre O.
The radius of a circle is any line segment connecting the centre of the circle to any point on the circle.
The chord of a circle is a line segment joining any two points on the circle.
The chord of a circle which passes through the centre of the circle is called the diameter of the circle. The diameter of a circle is the distance across a circle. The diameter is also the longest chord of a circle.
Formula for the diameter of Circle
Diameter of a circle d = 2r, where r is the radius of the circle.
Find the radius and diameter of the following circle.
Given Radius r = 18 cm
So Diameter = 2r = 2(18) = 36 cm
So, Radius = 18 cm, Diameter = 36 cm
Identify the radius, diameter, and chord from given circle.
The chord is Chord QP
The diameter is Diameter MN