eVidyarthi

Main Menu
  • eVidyarthi
  • School
    • Class 6th
      • Maths Class 6
      • Science Class 6
      • Hindi Class 6
      • Vyakaran
      • English Class 6
      • English Grammar
      • Sanskrit Class 6
      • Geography Class 6
      • Civics Class 6
      • History Class 6
    • Class 7th
      • Maths Class 7
      • Science Class 7
      • Hindi Class 7
      • Vyakaran
      • English Class 7
      • English Grammar
      • Sanskrit Class 7
      • Geography Class 7
      • Civics Class 7
      • History Class 7
    • Class 8th
      • Maths Class 8
      • Science Class 8
      • Hindi Class 8
      • Vyakaran
      • English Class 8
      • English Grammar
      • Sanskrit Class 8
      • Geography Class 8
      • Civics Class 8
      • History Class 8
    • Class 9th
      • Maths Class 9
      • Science Class 9
      • Hindi Class 9
      • व्याकरण
      • English Class 9
      • English Grammar
      • Economics Class 9
      • Geography Class 9
      • Civics Class 9
      • History Class 9
      • Sanskrit Class 9
    • Class 10th
      • Maths Class 10
      • Science Class 10
      • Hindi Class 10
      • Vyakaran
      • English Class 10
      • English Grammar
      • Economics Class 10
      • Geography Class 10
      • Civics Class 10
      • History Class 10
      • Sanskrit Class 10
    • Class 11
      • Maths Class 11
      • English Class 11
      • Hindi Class 11
      • Accounts Class 11
      • Physics Class 11
      • Chemistry Class 11
      • Biology Class 11
      • Economics Class 11
      • Geography Class 11
      • History Class 11
      • Political Science Class 11
      • Sociology Class 11
    • Class 12
      • Maths Class 12
      • English Class 12
      • Hindi Class 12
      • Accounts Class 12
      • Physics Class 12
      • Chemistry Class 12
      • Biology Class 12
      • Economics Class 12
      • Geography Class 12
      • History Class 12
      • Political Science Class 12
      • Sociology Class 12
    • Close
  • School – हिन्दी माध्यम
    • Class 6
      • Hindi Class 6
      • English Grammar
      • Vyakaran
      • Ganit Class 6
      • Vigyan Class 6
      • Samajik Vigyan Class 6
      • English Class 6
      • संस्कृत Class 6
    • Class 7
      • Hindi Class 7
      • English Grammar
      • Vyakaran
      • गणित Class 7
      • विज्ञान Class 7
      • सामाजिक विज्ञान Class 7
      • English Class 7
      • Sanskrit Class 7
    • Class 8
      • Hindi Class 8
      • English Grammar
      • Vyakaran
      • गणित Class 8
      • विज्ञान Class 8
      • सामाजिक विज्ञान Class 8
      • English Class 8
      • Sanskrit Class 8
    • Class 9
      • Hindi Class 9
      • English Grammar
      • Vyakaran
      • गणित Class 9
      • विज्ञान Class 9
      • सामाजिक विज्ञान Class 9
      • English Class 9
      • Sanskrit Class 9
    • Class 10
      • Hindi Class 10
      • English Grammar
      • Vyakaran
      • गणित Class 10
      • विज्ञान Class 10
      • सामाजिक विज्ञान Class 10
      • English Class 10
      • Sanskrit Class 10
    • Class 11
      • गणित Class 11
      • English Class 11
      • Hindi Class 11
      • अर्थशास्त्र Class 11
      • भूगोल Class 11
      • इतिहास Class 11
      • राजनितिक विज्ञान
      • समाजशास्त्र Class 11
      • भौतिक विज्ञान Class 11
      • रसायन विज्ञान Class 11
      • जीव विज्ञान Class 11
    • Class 12
      • गणित Class 12
      • English Class 12
      • Hindi Class 12
      • अर्थशास्त्र Class 12
      • भूगोल Class 12
      • इतिहास Class 12
      • राजनितिक विज्ञान
      • समाजशास्त्र Class 12
      • भौतिक-विज्ञान Class 12
      • रसायन विज्ञान Class 12
      • जीव विज्ञान Class 12
    • Close
  • बिहार बोर्ड
    • Class 6
      • हिंदी Class 6
      • Vyakaran
      • English Grammar
      • गणित Class 6
      • विज्ञान Class 6
      • English Class 6
      • सामाजिक विज्ञान Class 6
      • Sanskrit Class 6
    • Class 7
      • हिंदी Class 7
      • Vyakaran
      • English Grammar
      • गणित Class 7
      • विज्ञान Class 7
      • English Class 7
      • सामाजिक विज्ञान Class 7
      • Sanskrit Class 7
    • Class 8
      • हिंदी Class 8
      • Vyakaran
      • English Grammar
      • गणित Class 8
      • विज्ञान Class 8
      • English Class 8
      • सामाजिक विज्ञान Class 8
      • Sanskrit Class 8
    • Class 9
      • हिंदी Class 9
      • Vyakaran
      • English Grammar
      • गणित Class 9
      • विज्ञान Class 9
      • English Class 9
      • सामाजिक विज्ञान Class 9
      • Sanskrit Class 9
    • Class 10
      • हिंदी Class 10
      • Vyakaran
      • English Grammar
      • गणित Class 10
      • विज्ञान Class 10
      • English Class 10
      • सामाजिक विज्ञान Class 10
      • Sanskrit Class 10
    • Close
  • English
    • Basic English Grammar
    • Basic English Speaking
    • English Vocabulary
    • English Idioms & Phrases
    • Personality Enhancement
    • Interview Skills
    • Close
  • Softwares
    • Microsoft Word
    • PhotoShop
    • Excel
    • Illustrator
    • PowerPoint
    • Close
Maths Class 7 || Menu
  • MCQ Maths Class 7
  • Notes Maths Class 7
  • NCERT Solutions
  • Important Formulas Maths Class 7
  • Sample Paper Maths Class 7
  • Previous Year Paper Maths Class 7
  • Book Maths Class 7
  • Integers
    • Ex 1.1
    • Ex 1.2
    • Ex 1.3
    • Ex 1.4
    • MCQs
    • Close
  • Fractions and Decimals
    • Ex 2.1
    • Ex 2.2
    • Ex 2.3
    • Ex 2.4
    • Ex 2.5
    • Ex 2.6
    • Ex 2.7
    • MCQs
    • Close
  • Data Handling
    • Ex 3.1
    • Ex 3.2
    • Ex 3.3
    • Ex 3.4
    • MCQs
    • Close
  • Simple Equations
    • Ex 4.1
    • Ex 4.2
    • Ex 4.3
    • Ex 4.4
    • MCQs
    • Close
  • Lines and Angles
    • Ex 5.1
    • Ex 5.2
    • MCQs
    • Close
  • Triangle and its Properties
    • Ex 6.1
    • Ex 6.2
    • Ex 6.3
    • Ex 6.4
    • Ex 6.5
    • MCQs
    • Close
  • Congruence of Triangles
    • Ex 7.1
    • Ex 7.2
    • MCQs
    • Close
  • Comparing Quantities
    • Ex 8.1
    • Ex 8.2
    • Ex 8.3
    • MCQs
    • Close
  • Rational Numbers
    • Ex 9.1
    • Ex 9.2
    • MCQs
    • Close
  • Practical Geometry
    • Ex 10.1
    • Ex 10.2
    • Ex 10.3
    • Ex 10.4
    • Ex 10.5
    • MCQs
    • Close
  • Perimeter and Area
    • Ex 11.1
    • Ex 11.2
    • Ex 11.3
    • Ex 11.4
    • MCQs
    • Close
  • Algebraic Expressions
    • Ex 12.1
    • Ex 12.2
    • Ex 12.3
    • Ex 12.4
    • MCQs
    • Close
  • Exponents & Powers
    • Ex 13.1
    • Ex 13.2
    • Ex 13.3
    • MCQs
    • Close
  • Symmetry
    • Ex 14.1
    • Ex 14.2
    • Ex 14.3
    • MCQs
    • Close
  • Visualising Solid Shapes
    • Ex 15.1
    • Ex 15.2
    • Ex 15.3
    • Ex 15.4
    • MCQs
    • Close
Share on WhatsApp

Class 7 Ex. 5.1 Maths NCERT Solutions

Ads

Solutions For All Chapters Maths Class 7

NCERT Solutions for Class 7 Maths Chapter 5 Lines and Angles Ex 5.1

Ex 5.1 Class 7 Maths Question 1.
Find the complement of each of the following angles:

Solution:

(i) Complement of 20° = 90° – 20° = 70°
(ii) Complement of 63° = 90° – 63° = 27°
(iii) Complement of 57° = 90° – 57° = 33°

Ex 5.1 Class 7 Maths Question 2.
Find the supplement of each of the following angles:

Solution:

(i) Supplement of 105° = 180° – 105° = 75°
(ii) Supplement of 87° = 180° – 87° = 93°
(iii) Supplement of 154° = 180° – 154° = 26°

Ex 5.1 Class 7 Maths Question 3.
Identify which of the following pairs of angles are complementary and which are supplementary?
(i) 65°, 115°
(ii) 63°, 27°
(iii) 112°, 68°
(iv) 130°, 50°
(v) 45°, 45°
(vi) 80°, 10°

Solution:

(i) 65° (+) 115° = 180°
They are supplementary angles.
(ii) 63° (+) 27° = 90°
They are complementary angles.
(iii) 112° (+) 68° = 180°
They are supplementary angles.
(iv) 130° (+) 50° = 180°
They are supplementary angles.
(v) 45° (+) 45° = 90°
They are complementary angles.
(vi) 80° (+) 10° = 90°
They are complementary angles.

Ex 5.1 Class 7 Maths Question 4.
Find the angle which equal to its complement.

Solution:

Let the required angle be x°.
its complement = (90 – x)°
Now, re = 90 – x ⇒ x + x = 90
⇒ 2x = 90 ∴ x = 90/2 = 45°
Thus the required angles are 45°.

Ex 5.1 Class 7 Maths Question 5.
Find the angle which is equal to its supplement.

Solution:

Let the required angle be x°.
∴ it supplement = (180 – x)°
Now, x = 180 – x
⇒ x + x = 180
⇒ 2x = 180°
∴ x = 180°/2 =90°
Thus, the required angle is 90°.

Ex 5.1 Class 7 Maths Question 6.
In the given figure, ∠1 and ∠2 are supplementary angles.
If ∠1 is decreased, what changes should take place in∠2 so that both the angles still remain supplementary.

Solution:

∠1 + ∠2 = 180° (given)
If ∠1 is decreased by some degrees, then ∠2 will also be increased by the same degree so that the two angles still remain supplementary.

Ex 5.1 Class 7 Maths Question 7.
Can two angles be supplementary if both of them are:
(i) acute?
(ii) obtuse?
(iii) right?

Solution:

(ii) Since, acute angle < 90°
∴ Acute angle + acute angle < 90° + 90° < 180° Thus, the two acute angles cannot be supplementary angles. (ii) Since, obtuse angle > 90°
∴ Obtuse angle + obtuse angle > 90° + 90° > 180°
Thus, the two obtuse angles cannot be supplementary angles.
(iii) Since, right angle = 90°
∴ right angle + right angle = 90° + 90° = 180°
Thus, two right angles are supplementary angles.

Ex 5.1 Class 7 Maths Question 8.
An angle is greater than 45°. Is its complementary angle greater than 45° or equal to 45° or less than 45 °?

Solution:

Given angle is greater than 45°
Let the given angle be x°.
∴ x > 45
Complement of x° = 90° – x° < 45° [ ∵ x > 45°]
Thus the required angle is less than 45°.

Ex 5.1 Class 7 Maths Question 9.
In the following figure:
(i) Is ∠1 adjacent to ∠2?

(ii) Is ∠AOC adjacent to∠AOE?

(iii) Do ∠COE and ∠EOD form a linear pair?

(iv) Are ∠BOD and ∠DOA supplementary?

(v) Is ∠1 vertically opposite angle to ∠4?

(vi) What is the vertically opposite angle of ∠5?

Solution:

(i) Yes, ∠1 and ∠2 are adjacent angles.
(ii) No, ∠AOC is not adjacent to ∠AOE. [ ∵ OC and OE do not lie on either side of common arm OA] .
(iii) Yes, ∠COE and ∠EOD form a linear pair of angles.
(iv) Yes, ∠BOD and ∠DOA are supplementary. [∵ ∠BOD + ∠DOA = 180°]
(v) Yes, ∠1 is vertically opposite to ∠4.
(vi) Vertically opposite angle of ∠5 is ∠2 + ∠3 i.e. ∠BOC.

Ex 5.1 Class 7 Maths Question 10.
Indicate which pairs of angles are:
(i) Vertically opposite angles
(ii) Linear pairs

Solution:

(i) Vertically opposite angles are ∠1 and ∠4, ∠5 and (∠2 + ∠3)

(ii) Linear pairs are
∠1 and ∠5, ∠5 and ∠4

Ex 5.1 Class 7 Maths Question 11.
In the following figure, is ∠1 adjacent to ∠2? Give reasons.

Solution:

No, ∠1 and∠2 are not adjacent angles.


Reasons:
(i) ∠1 + ∠2 ≠ 180°
(ii) They have no common vertex.

Ex 5.1 Class 7 Maths Question 12.
Find the values of the angles x, y and z in each of the following:

Solution:

From Fig. 1. we have
∠x = ∠55° (Vertically opposite angles)
∠x + ∠y = 180° (Adjacent angles)
55° + ∠y = 180° (Linear pair angles)
∴ ∠y = 180° – 55° = 125°
∠y = ∠z (Vertically opposite angles)
125° = ∠z
Hence, ∠x = 55°, ∠y = 125° and ∠z = 125°

(ii) 25° + x + 40° = 180° (Sum of adjacent angles on straight line)
65° + x = 180°
∴ x = 180° – 65° = 115°
40° + y = 180° (Linear pairs)
∴ y = 180° – 40° = 140°
y + z = 180° (Linear pairs)
140° + z = 180°
∴ z = 180° – 140° = 40°
Hence, x – 115°, y = 140° and z – 40°

Ex 5.1 Class 7 Maths Question 13.
Fill in the blanks:
(i) If two angles are complementary, then the sum of their measures is ______ .
(ii) If two angles are supplementary, then the sum of their measures is ______ .
(iii) Two angles forming a linear pair are ______ .
(iv) If two adjacent angles are supplementary, they form a ______ .
(v) If two lines intersect at a point, then the vertically opposite angles are always ______ .
(vi) If two lines intersect at a point, and if one pair of vertically opposite angles are acute angles, then the other pair of vertically opposite angles are ______ .

Solution:

(i) 90°
(ii) 180°
(iii) Supplementary
(iv) Linear pair
(v) Equal
(vi) Obtuse angle

Ex 5.1 Class 7 Maths Question 14.
In the given figure, name the following pairs of angles.

(i) Obtuse vertically opposite angles.
(ii) Adjacent complementary angles.
(iii) Equal supplementary angles.
(iv) Unequal supplementary angles.
(v) Adjacent angles but do not form a linear pair.

Solution:

(i) ∠BOC and ∠AOD are obtuse vertically opposite angles.
(ii) ∠AOB and ∠AOE are adjacent complementary angles.
(iii) ∠EOB and ∠EOD are equal supplementary angles.
(iv) ∠EOA and ∠EOC are unequal supplementary angles.
(v) ∠AOB and ∠AOE, ∠AOE and ∠EOD, ∠EOD and ∠COD are adjacent angles but do not form a linear pair.

Ads

Android App

eVidyarthi

Evidyarthi on Facebook

Like us on Facebook

YouTube Channels

Social Science Class 6
Social Science Class 8
Learn English
English Through हिन्दी
Job Interview Skills
English Grammar
हिंदी व्याकरण - Vyakaran
Mathematics Class 6th
Social Science Class 6
Science Class 6th
हिन्दी Class 6th
Mathematics Class 7th
Science Class 7th
हिन्दी Class 7th
Mathematics Class 8th
Social Science Class 8
Social Science Class 8
Science Class 8th
हिन्दी Class 8th
Mathematics Class 9th
English Class 9th
Science Class 9th
Mathematics Class 10th
English Class 10th
Mathematics Class XI
Chemistry Class XI
Accountancy Class 11th
Accountancy Class 12th
Mathematics Class 12th
Microsoft Word
Microsoft Excel
Microsoft PowerPoint
Adobe PhotoShop
Adobe Illustrator
Learn German
Learn French
IIT JEE
Privacy Policies, Contact Us
Copyright © 2022 eVidyarthi and its licensors. All Rights Reserved.