Students can Download Maths Chapter 5 Squares, Square Roots, Cubes, Cube Roots Ex 5.3 Questions and Answers, Notes Pdf, KSEEB Solutions for Class 8 Maths helps you to revise the complete Karnataka State Board Syllabus and score more marks in your examinations.

## Karnataka Board Class 8 Maths Chapter 5 Squares, Square Roots, Cubes, Cube Roots Ex 5.3

Question 1.

Find the squares of

(i) 31

(ii) 72

(iii) 37

(iv) 166

Answer:

(i) 31^{2} = (30 + 1)^{2}

= 30^{2} + 2 × 30 ×1 + 1^{2}

= 900 + 60 +1

= 961

(ii) 72^{2} = (70 + 2)^{2}

= 70^{2} + 2 × 70 × 2 + 2^{2}

= 4900 + 280 + 4

= 5184

(iii) 37^{2} = (30 + 7)^{2}

= 30^{2} + 2 × 30 × 7 + 7^{2}

= 900 + 420 + 49

= 1369

(iv) 166^{2} = (160 + 6)^{2}

= 160^{2} + 2 × 160 × 6 + 6^{2}

= 25600 + 1920 + 36

= 27556

Question 2.

Find the squares of.

(i) 85

(ii) 115

(iii) 165

Answer:

(i) 85^{2} = (80 + 5)^{2}

= 80^{2} + 2 × 80 × 5 + 5^{2}

= 6400 + 800 + 25 = 7225

(ii) 115^{2} = ( 100 + 15)^{2}

= 100^{2} + 2 × 100 × 15 + 15^{2}

= 10,000 + 3000 + 225 = 13225

(iii) 165^{2}=( 150+15)^{2}

= 150^{2} + 2 × 150 × 15 + 15^{2}

= 22500 + 4500 + 225 = 27225

Question 3.

Find the square of 1468 by writing this as 1465 + 3.

Answer:

First find the square of 1465.

\((1465)^{2}=(146 \times 147) 25\) [Statement 9]

(1465)^{2} = (146 × 147)25 [Statement 9]

(1465)^{2} = 2146225

(1465 + 3)^{2} = 1465^{2} + 2 × 1465 × 3 + 3^{2}

= 2146225 + 8790 + 9

(1468)^{2} = 2155024