4.5.1
Properties of a Circle
Circle Basics
Circle Basics


Radius
Radius
- A straight line from the centre of a circle to its edge is called a radius.


Diameter
Diameter
- A straight line from one side of the circle to the other that passes through the centre is called a diameter.


Circumference
Circumference
- The circumference of a circle is the distance around the circle, the length of its edge.
Chords in a Circle
Chords in a Circle
A chord is a line that passes from one side of the circle to the other. It doesn't have to go through the middle of the circle.


Splits circumference
Splits circumference
- A chord splits the circumference (edge of circle) into two arcs.
- The larger arc is called the major arc and the smaller is called the minor arc.


Splits area
Splits area
- A chord splits the area of a circle into two parts called segments.
- The larger segment is called the major segment and the smaller one is called the minor segment.


Arc
Arc
- When two chords meet at a point, we say the angle x is subtended by the arc between A and C.
Circle Properties
Circle Properties


Tangent
Tangent
- A tangent is a line that just touches the edge of the circle.


Sectors
Sectors
- Two radii split the circle into two parts called sectors.
- The larger sector is called the major sector, the smaller is called the minor sector.


Two radii form an isosceles triangle
Two radii form an isosceles triangle
- This is because the radii of a circle are always the same length.
1Numbers
1.1Integers
1.3Decimals
1.4Powers & Roots
1.5Set Language & Notation
1.6Percentages
1.7Ratio & Proportion
2Equations, Formulae & Identities
2.1Algebraic Manipulation
2.2Expressions & Formulae
2.3Linear Equations
2.4Quadratic Equations
2.5Proportion
3Sequences, Functions & Graphs
3.1Sequences
3.3Graphs
3.4Common Graphs
4Geometry
4.1Angles, Lines & Triangles
4.2Polygons
4.5Circle Properties
4.6Trigonometry & Pythagoras’ theorem
4.7Mensuration of 2D Shapes
4.83D Shapes & Volume
5Vectors & Transformation Geometry
6Statistics & Probability
6.1Statistical Measures
6.2Graphical Representation of Data
Jump to other topics
1Numbers
1.1Integers
1.3Decimals
1.4Powers & Roots
1.5Set Language & Notation
1.6Percentages
1.7Ratio & Proportion
2Equations, Formulae & Identities
2.1Algebraic Manipulation
2.2Expressions & Formulae
2.3Linear Equations
2.4Quadratic Equations
2.5Proportion
3Sequences, Functions & Graphs
3.1Sequences
3.3Graphs
3.4Common Graphs
4Geometry
4.1Angles, Lines & Triangles
4.2Polygons
4.5Circle Properties
4.6Trigonometry & Pythagoras’ theorem
4.7Mensuration of 2D Shapes
4.83D Shapes & Volume
5Vectors & Transformation Geometry
6Statistics & Probability
6.1Statistical Measures
6.2Graphical Representation of Data
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