Q2 of 22 Page 68

Let's draw a straight line AB and consider a point P on the line AB. Let's erect a ray from P on the straight line AB. As a result two adjacent angles are formed. Now we measure the adjacent angles and examine whether the sum of the measurement of those angles is 180° or not.

First, draw a straight line, naming it A.


Now, consider a point P anywhere on AB.



Now, from that P point, draw a ray in any direction.



Or,



We see that two adjacent angles are formed.


In either case, we can measure the angles by a protractor.


Let us take this,



In this case,


60° + 120° = 180°


Similarly, in every case,


If a straight line is partitioned, then the sum of (any) adjacent angles will be 180° every time.


More from this chapter

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1

Let's find which pair of angles are complementary or supplementary among the following pairs of angles and then draw:

10°, 170°; 38°, 52°; 35°, 65°; 90°, 90°; 25°, 165°; 45°, 45°


 1

Which of following figures having the sun I adjacent angles as two right angles?


 1 A

Let’s think and write:

Let’s write whether two acute angles are complementary to each other.


 1 B

Let’s think and write:

Let’s write whether two acute angles are supplementary to each other.