ML Aggarwal Solutions for Class 7 Maths Chapter 10- Lines and Angles

Class 7: Maths Chapter 10 solutions. Complete Class 7 Maths Chapter 10 Notes.

ML Aggarwal Solutions for Class 7 Maths Chapter 10- Lines and Angles

ML Aggarwal 7th Maths Chapter 10, Class 7 Maths Chapter 10 solutions

1. (i) Can two right angles be complementary?(ii) Can two right angles be supplementary?(iii) Can two adjacent angles be complementary?(iv) Can two adjacent angles be supplementary?(v) Can two obtuse angles be adjacent?(vi) Can an acute angle be adjacent to an obtuse angle?(vii) Can two right angles form a linear pair?

Solution:

(i) No, as the sum of two complementary angles is 90^o.

(ii) Yes

(iii) Yes

(iv) Yes

(v) Yes

(vi) Yes

(vii) Yes

2. Find the complement of each of the following angles:

Solution:

(i) Complement of 25^o is 90^o – 25^o = 65^o.

(ii) Complement of 63^o is 90^o – 63^o = 27^o.

(iii) Complement of 57^o is 90^o – 57^o = 33^o.

3. Find the supplement of each of the following angles:

Solution:

(i) Supplement of 105^o is 180^o – 105^o = 75^o.

(ii) Supplement of 87^o is 180^o – 87^o = 93^o.

(iii) Supplement of 142^o is 180^o – 142^o = 38^o.

4. Identify which of the following pairs of angles are complementary and which are supplementary:
(i) 55°, 125°
(ii) 34°, 56°
(iii) 137°, 43°
(iv) 112°, 68°
(v) 45°, 45°
(vi) 72°, 18°
Solution:

(i) 55°, 125° are supplementary angles.

(ii) 34°, 56° are complementary angles.

(iii) 137°, 43° are supplementary angles.

(iv) 112°, 68° are supplementary angles.

(v) 45°, 45° are complementary angles.

(vi) 72°, 18° are complementary angles.

5. (i) Find the angle which is equal to its complement.
(ii) Find the angle which is equal to its supplement.
Solution:

(i) The angle which is equal to its complement is

90/2 = 45^o.

So, 45^o is complement to 45^o.

(ii) The angle which is equal to its supplement is

180/2 = 90^o.

So, 90^o is supplement to 90^o.

6. Two complementary angles are (x + 4)° and (2x – 7)°, find the value of x.
Solution:

Given:

Two complementary angles are (x + 4)° and (2x – 7)°

x + 4 + 2x – 7 = 90^o

3x – 3 = 90^o

3x = 90 + 3

3x = 93

x = 93/3

x = 31^o

∴ Value of x is 31^o.

7. Two supplementary angles are in the ratio of 2: 7, find the angles.
Solution:

Given:

Two supplementary angles are in the ratio of 2: 7

We know the sum of the angles is 180^o.

So, first angle = [180^o/(2+7)] × 2

= (180/9) × 2

= 40^o

Second angle = [180^o/(2+7)] × 7

= (180/9) × 7

= 140^o

∴ The angles are 40^o and 140^o.

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ML Aggarwal Solutions for Class 7 Maths Chapter 10- Lines and Angles

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Chapterwise ML Aggarwal Solutions for Class 7 Maths :

• Chapter 1- Integers
• Chapter 2- Fractions and Decimals
• Chapter 3- Rational Numbers
• Chapter 4- Exponents and Powers
• Chapter 5- Sets
• Chapter 6- Ratio and Proportion
• Chapter 7- Percentage and Its Applications
• Chapter 8- Algebraic Expressions
• Chapter 9- Linear Equations and Inequalitie
• Chapter 10- Lines and Angles
• Chapter 11- Triangles and its Properties
• Chapter 12- Congruence of Triangles
• Chapter 13- Practical Geometry
• Chapter 14- Symmetry
• Chapter 15- Visualising Solid Shapes
• Chapter 16- Perimeter and Area
• Chapter 17- Data Handling

About ML Aggarwal

M. L. Aggarwal, is an Indian mechanical engineer, educator. His achievements include research in solutions of industrial problems related to fatigue design. Recipient Best Paper award, Manipal Institute of Technology, 2004. Member of TSTE.