By

Krishna Kumar Sahu

TGT - MATHS

Kendriya Vidyalaya NO. 2 CPE ITARSI

How many types of How many types of anglesangles ?. ?.

Vertically Opposite Angles.Vertically Opposite Angles. Alternate interior Angles.Alternate interior Angles. Alternate Exterior Angles.Alternate Exterior Angles. Corresponding Angles.Corresponding Angles. Linear pair of angles.Linear pair of angles. Interior Angles on the same side of a Interior Angles on the same side of a

Transversal.Transversal. End Show.End Show.

VERTICALLY OPPOSITE VERTICALLY OPPOSITE ANGLESANGLES

l

m

1

2

3

4

5

6

7

8

Here l & m are two lines , t is transversalThen t

1 ,

3

2 , 4

5 , 7

6 , 8

Vertically OppositeAngles

If two lines are intersecting each other then vertically opposite angles are always equal.So

1 = 3 , 2 = 4 , 5 = 7 , 6 = 8

Alternate Interior AnglesAlternate Interior AnglesHere l & m are two lines, t is a transversalHere l & m are two lines, t is a transversalthenthen

1 , 4

2 , 3

AlternateInteriorAngles

1 2

3 4l

m

t

If two lines are parallel to each other then alternate interior angles are equal

1 = 4 , 2 = 3

1 2

3 4

CORRESPONDING ANGLESCORRESPONDING ANGLESHere l & m are two lines , t is transversalThen

1 ,

3

2 , 4

5 , 7

6 , 8

CorrespondingAngles

If two lines are parallel to each other then corresponding angles are always equal.So

1 = 3 , 2 = 4 , 5 = 7 , 6 = 8

1 2

3 4l

m

t

12

3 4

5

7

6

8

78

5 6

CORRESPONDING ANGLESCORRESPONDING ANGLESAlternate Exterior Angles.Alternate Exterior Angles.

Here l & m are two lines, t is a transversalHere l & m are two lines, t is a transversalthenthen

1 , 4

2 , 3

AlternateexteriorAngles

1 2

3 4

l

m

t

If two lines are parallel to each other then alternate exterior angles are equal

1 = 4 , 2 = 3

12

34

Interior angles on the same side of a Interior angles on the same side of a transversaltransversal

Here l & m are two lines, t is a transversalHere l & m are two lines, t is a transversalthenthen

2 , 4

1 , 3

Pair of interior angles on the same side of transversal

1 2

3 4l

m

t

If two lines are parallel to each other then sum of interior angles on the same side of transversal is 180.

2 + 4 = 180 &

1 + 3 = 180 1 2

3 4

Linear pair of anglesLinear pair of angles

Angles on a straight line is Linear pair of angles & their sum is always equal to 180o.

A BC

A B C

D

ACB = 1800

ABD +

DBC = 1800

Two adjacent angles form a linear pair.

Two acute angles not form a linear pair.

Two obtuse angle not form a linear pair.

One obtuse and one acute angle form a linear pair.

Two right angles form a linear pair.