Free Study Material For RRB Examination
Subject : Mathematics (Concepts of Geometry)
A point is defined by its position. It has no length, width or
thickness. A straight line joining two points is the shortest distance between
them. Three or more points are said to be collinear, if there is a line which
contains all of them.
A line is defined by its length and has no breadth. It has
length units. (metre, foot, centimetre kilometre, etc.).
A line contains infinite points. Through a given point, there
pass infinite lines. One and only one straight line passes through two distinct
points. Three or more lines are said to be concurrent, if they pass, through one
point and that point is called the point of concurrence. Two lines are said to
be intersecting lines, if they have a common point.
When two straight lines meet at a point, they are said to form
an angle. Angles generally are measured in degrees. There are 180° in a straight
line and a full circle constitutes 360°.
1. Two angles are said to be complementary, if their sum is 90°.
Complement of x is (90° – x).
2. Two angles are said to be supplementary, if their sum is
180°. Supplement of x is (180° – x).