.jpg "Lines And Angles")
We recall that
(i) A line-segment has two end points.
(ii) A ray has only one end point (its vertex); and
(iii) A line has no end points on either side.
- An angle is formed when two lines (or rays or line-segments) meet.
| Pairs of Angles | Condition |
| Two complementary angles | Measures add up to  |
| Two supplementary angles | Measures add up to  |
|
Two adjacent angles |
Have a common vertex and a common arm but no common interior. |
| Linear pair | Adjacent and supplementary |
- When two lines l and m meet, we say they intersect; the meeting point is called the point of intersection.
- When lines drawn on a sheet of paper do not meet, however far produced, we call them to be parallel lines.
- Point: A point name a location.
- Line: A line is perfectly straight and extends forever in both direction.
- Line segment: A line segment is the part of a line between two points.
- Ray: A ray is part of a line that starts at one point and extends forever in one direction.
- Intersecting lines: Two or more lines that have one and only one point in common. The common point where all the intersecting lines meet is called the point of intersection.
- Transversal: A line intersects two or more lines that lie in the same plane in distinct points.
- Parallel lines: Two lines on a plane that never meet. They are always the same distance apart.
- Complementary Angles: Two angles whose measures add to .
- Supplementary Angles: Two angles whose measures add to
- Adjacent Angles: Two angles have a common vertex and a common arm but no common interior points.
- Linear pairs: A pair of adjacent angles whose non-common sides are opposite rays.
- Vertically Opposite Angles: Two angles formed by two intersecting lines have common arm.
- Angles made by Transversal: When two lines are intersecting by a transversal, eight angles are formed.
- Transversal of Parallel Lines: If two parallel lines are intersected by a transversal, each pair of:
Corresponding angles are congruent.
Alternate interior angles are congruent.
Alternate exterior angles are congruent.
If the transversal is perpendicular to the parallel lines, all of the angles formed are congruent to angles.
For More :-
CBSE
Class–VII | CHAPTER – 1 Integers | NMMS
Revision Notes à Click Here
Tracing
Changes Through a Thousand Years | NMMS Revision Notes | Class 7 | Social à Click Here
New
Kings and Kingdoms | NMMS Revision Notes | Class 7 | Social à Click Here
The
Delhi Sultanate | NMMS Revision Notes | Class 7 Social à Click Here
The
Mughal Empire | NMMS Revision Notes | Class 7 Social à Click Here
Tribes
Nomads and Settled Communities | NMMS Revision Notes | Class 7 Social à Click Here
Devotional
Paths to the Divine | NMMS Revision Notes | Class 7 Social à Click Here
The
Making of Regional Cultures | NMMS Revision Notes | Class 7 Social à Click Here
Eighteenth
Century Political Formations | NMMS Revision Notes | Class 7 Social à Click Here
Environment
| NMMS Revision Notes | Class 7 Social à Click Here
Inside
Our Earth | NMMS Revision Notes | Class 7 Social à Click Here
Our
Changing Earth | NMMS Revision Notes | Class 7 Social à Click Here
Air |
NMMS Revision Notes | Class 7 Social à Click Here
Water
| NMMS Revision Notes | Class 7 Social à Click Here
Human
Environment Interactions the Tropical | NMMS Revison Notes | Class 7 Social à Click Here
Life
in the Deserts | NMMS Revision Notes | Class 7 Social à Click Here
On
Equality | NMMS Revision Notes | Class 7 Social à Click Here
How
the State Government Works | NMMS Revision Notes | Class 7 Social à Click Here
Role
of the Government in Health | NMMS Revision Notes | Class 7 Social à Click Here
Growing
up as Boys and Girls | NMMS Revision Notes | Class 7 Social à Click Here
Women
Change the World | NMMS Revision Notes | Class 7 Social à Click Here
Understanding
Media | NMMS Revision Notes | Class 7 Social à Click Here
Markets
Around Us | NMMS Revision Notes | Class 7 Social à Click Here
A
Shirt in the Market | NMMS Revision Notes | Class 7 Social à Click Here
Nutrition
in Plants | NMMS Revision Notes | Class 7 Science à Click Here
Nutrition
in Animals | NMMS Revision Notes | Class 7 Science à Click Here
Heat |
NMMS Revision Notes | Class 7 Science à Click Here
Acids
Bases And Salts | NMMS Revision Notes | Class 7 Science à Click Here
Physical
And Chemical Changes | NMMS Revision Notes | Class 7 Science à Click Here
Respiration
In Organisms | NMMS Revision Notes | Class 7 Science à Click Here
Transportation
in Animals and Plants | NMMS Revision Notes | Class 7 Science à Click Here
Force
and Pressure | NMMS Quick Revision Notes
| Class: 8 Physics à
Click Here
Reproduction
In Plants | NMMS Revision Notes | Class 7 Science à Click Here
Motion
And Time | NMMS Revision Notes | Class 7 Science à Click Here
Electric
Current and its Effects | NMMS Revision Notes | Class 7 Science à Click Here
Light
| NMMS Revision Notes | Class 7 Science à Click Here
Waste
Water Story | NMMS Revision Notes | Class 7 Science à Click Here
How
When and Where | NMMS Revision Notes | Class 8 Social à Click Here
From
Trade to Territory | NMMS Revision Notes | Class 8 Social à Click Here
Ruling
the Countryside | NMMS Revision Notes | Class 8 Social à Click Here
Tribals
Dikus and Vision of Golden Age | NMMS Revision Notes | Class 8 Social à Click Here
When
People Rebel | NMMS Revision Notes | Class 8 Social à Click Here
Weavers
Iron Smelters and Factory Owners | NMMS Revision Notes | Class 8 Social à Click Here
Civilising
the Native Educating the Nation | NMMS Revision Notes | Class 8 Social à Click Here
Women
Caste and Reform | NMMS Revision Notes | Class 8 Social à Click Here