Parallel lines, perpendicular lines, geometry

Hello children, in this session we will discuss about one of the most interesting topics of mathematics- geometry . First question that arises in mind is, what is geometry? When we study about shape and size of a figure in space than this study is called as a geometry. For insrance, a persaon draws a figure of his house and then analyzes that figure. This process of analyzing figures is known as a geometry.

Fundamentals of geometry -

Point and line are two fundamentals concepts of geometry. When you touch the tip of your pen on paper then a dot is made. This dot is a point. For understanding the definition of a point, have a look at the figure below:

This figure is called as point . So, we can say that point is a dimensionless location in space (here dimensionless means there is no length , no height and no width .)
The next fundamental concept of geometry is a line . When we join two points , one figure is created and this figure is called as a  line .
A <-----------------------------------------> B
AB is a line.
There are two type of lines in space –

1. Parallel lines
2. Perpendicular lines
   

Parallel Lines Definition : Two lines which never meet in space , then these two lines are known as a Parallel lines or in other word two lines which always  maintain same distance between them are said to be Parallel lines.

In the figure, line1 and line2 are patallel to each other. One can observe that the didtanve between two lines is always same.
Now, we will discuss properties of Parallel lines . These lines have following  properties –

• Parallel lines never intersect each other.
• Distance between parallel lines always remains constant for each and every point .
• Parallel lines always remain in same plane .
  

Perpendicular lines  :  Two lines which intersect with each other at right angle i.e. intersect at 90 degree angle are called as perpendicular lines .

In the figure line 1 and line 2 are perpendicular to each other and meet at point O. Point O is called the point of intersection of the perpendicular lines.

perpendicular lines have following properties –

• Perpendicular lines always intersect each other at 90 degree .
• Perpendicular lines always remain in same plane .

So, this is all about geometry portion of grade IV .

In upcoming posts we will discuss about Symmetry of geometric figures and grade V. Visit our website for information on Andhra Pradesh geography questions