A point(dot) is a small mark that has position,but no magnitude. A dot has neither shape nor size. It is represented by a small dot and denoted by a capital letter like dot 'P', dot 'Q' and dot 'R' as shown here.

The tip of a nail or pin can be taken as a physical model of a dot. In reality,a dot in geometry is even smaller than the tip of a nail or pin.

There are two types of dots 1) Collinear 2) non-collinear.

1) Collinear : If three or more dots on the same plane lie on the same line, they are known as collinear .

Example :

Dots A, B,C and D which lie on line l are collinear . Line l is known as the Line of collinearity.

2) Non-collinear : If three or more dots on the same plane do not lie on the same line, they are known as non- collinear.

Example :

The dots P,Q and R are non-collinear .


Q.1 State whether the following statements are true or false.

i) A dot has no length and no width.

ii) A dot has thickness.

iii) An infinite number of dots lie on a circle.

iv) Non-collinear dots lie on straight line.

v) A dot shows the exact location.

Q.2 From the given figure state which dots are collinear and which are non-collinear.


i) True

ii) False. ( A dot has no thickness.)

iii) True

iv) False ( Non-collinear dots do not lie on straight line.)

v) True

Q.2 P and Q, Q and R & P and R are collinear.
P,Q, R are non collinear.
Basic Geometry

Lines and Angles
Complementary angles
Supplementary angles
Vertically Opposite Angles
Linear Pair Angles
Adjacent Angles
Parallel Lines
Solved Problems on Intersecting Lines
Solved Problems on Parallel Lines

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