**Collins Maths Solutions Class 7 Chapter 13 Lines and Angles**

Welcome to NCTB Solution. Here with this post we are going to help 7th class students for the Solutions of Collins Maths Class 7 Mathematics, Chapter 13, Lines and Angles. Here students can easily find chapter 7 solutions with exercise wise explanation. Students will find proper solutions for Exercise 13.1 and 13.2 Our teacher’s solved every problem with easily understandable methods so that every students can understand easily. Here in this post all the solutions are based on ICSE latest Syllabus.

**Lines and Angles Exercise 13.1 Solution :**

**Question no – (1) **

**Solution : **

Angle is

= (180° + 40°)

= 220°

Therefore, the angle will be 220°.

**Question no – (2) **

**Solution : **

60′ ………………. 360°

**∴** 5′ ……………… 360°/60 × 5

= 30°

**∴ **At 7o’ clock,

Obtuse angle = (180° – 30°)

= 150°

And, Reflex angle,

= (360 – 150)

= 210°

Therefore, measures of these angles will be 150° and 210°.

**Question no – (3) **

**Solution : **

At 11’0 clock,

Acute angle = 5 min

= (5 × 6)

= 30°

And, Reflex angle,

= (360° – 30°)

= 330°

Therefore, measures of these angles are 30° and 330°.

**Question no – (4) **

**Solutions : **

**(i) Two straight angles,**

= (2 × 180°)

= 360°

**(ii) 1 1/3 of a right angle**

= (1 1/3 × 90°)

= (4/3 × 90°)

= 120°

**(iii) 1/2 of a straight angle,**

= (1/2 × 180°)

= 90°

**(iv) 1/6 of a straight angle,**

= (1/6 × 180°)

= 30°

**Question no – (5) **

**Solution : **

Here, x + x + 40 = 90°

= 2x = 90° – 40

= x = 50/2

= x = 25°

Therefore, the value of x will be 25°.

**Question no – (7) **

**Solution : **

Here, x + x + 60° = 180°

= 2x = 180° – 60° = 120°

= x = 120/2

= x = 60°

Therefore, The value of x will be 60°.

**Question no – (8)**

**Solution : **

Let, angle be 3x and 6x

**∴** 6x + 3x = 90°

= 9x = 90°

= x = 90°/9

= x = 10°

**∴** 3x = 3 × 10 = 30°

And, 6 × 10 = 60°

**Question no – (8) **

**Solution : **

Let, the angle be 10x and 8x

**∴** 10x + 8x = 180°

= x = 180°/18

= x = 10°

**∴** Angles are = (10 × 10°) = 100°

and, (8 × 10°) = 80°

Therefore, the angles are 100° and 80°.

**Question no – (9)**

**Solution : **

The angle is 120°

**Question no – 10**

**Solution :**

Let, angle be x°

**∴** x + x – 40 = 90

= 2x = 90 + 40

= x = 130/2

= x = 65°

Hence, the measure of the angle will be 65°.

**Question no – (11)**

**Solution : **

Let, the angle be x°

**∴** x + x + 60 = 180°

= 2x = 180° – 60°

= x = 120/2

= x = 60°

Therefore, the measures of the angle will be 60°.

**Question no – (12)**

**Solution : **

Let, the angle be x°

**∴** x = 5 (180° – x) + 10

= x = 900 – 5x + 10

= 6x = 910/6

= x = 151.7°

Therefore, the angle will be 151.7°

**Next Chapter Solution : **

👉 Chapter 14 👈