PREPARED BY
MOHAMMAD RIZWAN
(H.M.)
Closed curves
A curve starts and ends at the same point.
Simple closed curves
A closed curve which does not cross itself is called a simple closed curve.
Polygons
Simple closed curves formed of three or more line segments are called polygons.
Triangle
A polygon formed by three line segments is called Triangle.
QUADRILATERAL
A polygon formed by four line segments is called a quadrilateral.
SQUARE, RECTANGLE
A Square and a Rectangle are special kinds of a quadrilateral.
CIRCLE
Terms related to Circle
CENTRE
Centre
Radius
O
P
A line segment drawn from the centre to any point on a circle
DIAMETER
Diameter
M
N
O
A line segment drawn through the centre that joins two points on a circle.
Chord
A
B
A line segment that joins two points on a circle.
D
K
A
B
O
The line segments A B and D K are the cords of the circle
The Diameter of a circle is also a Chord
Circumference
Length of the circle
is called
the
circumference of the circle
O
Radius
Diameter
The radius
is
always
half
of the
diameter
of a
circle
P
M
N