Welcome to Class !!

We are eager to have you join us !!

In today’s Basic Technology class, We will be discussing Circle. We hope you enjoy the class!



circle is a simple shape, consisting of those points in a plane that are a given distance from a given point – the centre.

Origin: The centre of a circle.

center or origin of a circle classnotesng


Radius: The distance from the centre of a circle to any point on it.

radius of a circle classnotes

Diameter: The longest distance from one end of a circle to the other. The diameter = 2 × radius (d = 2r).

diameter of a circle classnotes


Circumference: The distance around the circle.

circumference of a circle classnotesng

Circumference = π×diameter.

Circumference = π×d = 2×π×r


Arc: a curved line that is part of the circumference of a circle.

arc in a circle classnotesng

The arc of a circle is measured in degrees or radians – for example 90° or \displaystyle \frac{\pi}{2}2π​ – a quarter of the circle,
180° or \displaystyle \piπ – half of the circle.
The arc is smaller than 360°(or \displaystyle 2\pi2π) because that is the whole circle.


Chord: a line segment within a circle that touches 2 points on the circle.

a chord in  a circle classnotesng


Sector: is like a slice of pie (a circle wedge).

sector in a circle classnotesng


Tangent: a line perpendicular to the radius that touches ONLY one point on the circle.

tangent to a circle classnotesng



We have come to the end of this class. We do hope you enjoyed the class?

Should you have any further question, feel free to ask in the comment section below and trust us to respond as soon as possible.

We have come to the end of first term. Its been an amazing journey with you and we can’t wait for you to join us in Second Term!!


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