Point

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 .



Practice

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.

Answers

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

• Point
• Lines
• Angles
• 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

Home Page