Question

CLASS 9 MATH CHAPTER 1 EXERCISE 1.2 QUESTION 3 BTA DO?

Answer 1

Solution:

Step 1: Let line AB be of 2 unit on a number line.

Step 2: At B, draw a perpendicular line BC of length 1 unit.

Step 3: Join CA

Step 4: Now, ABC is a right angled triangle. Applying Pythagoras theorem,

AB2+BC2 = CA2

22+12 = CA2 CA2 = 5

⇒ CA = √5 . Thus, CA is a line of length √5 unit.

Step 4: Taking CA as a radius and A as a center draw an arc touching

the number line. The point at which number line get intersected by

arc is at √5 distance from 0 because it is a radius of the circle

whose center was A.

Thus, √5 is represented on the number line

Answer 2

√5 =4+1

Here 4 and 1 both are perfect square.

Number as

4=2 and 1=1

So draw a right angle triangle with side 2 and 1.

And according to Pythagoras theorem will be

22+1 2 =5