CBSE 9th Standard Mathematics Lines and Angles Model Questions Papers Study Material - QB365 Set D | QB365

9th Standard CBSE Syllabus & Materials

9th Standard CBSE

CBSE 9th Science Is matter around us pure? - New Model Questions Papers Study Material - QB365 Set A

NEW

9th Standard CBSE

CBSE 9th Science Matter in our surroundings - New Model Questions Papers Study Material - QB365 Set A

NEW

9th Standard CBSE

CBSE 9th Mathematics Heron's Formula Sample Question Papers Study Material - QB365 Set A

NEW

9th Standard CBSE

CBSE 9th Mathematics Circles Sample Question Papers Study Material - QB365 Set A

NEW

9th Standard CBSE

CBSE 9th Mathematics Quadrilaterals Sample Question Papers Study Material - QB365 Set A

NEW

9th Standard CBSE

CBSE 9th Mathematics Triangles Sample Question Papers Study Material - QB365 Set A

CBSE 9th Standard Mathematics Lines and Angles Model Questions Papers Study Material - QB365 Set D

Published on: 29/10/2025

Question Set D

CBSE 9th Standard Mathematics Lines and Angles Model Questions Papers Study Material - QB365

Download CBSE Class 9th Standard CBSE Mathematics question papers, sample papers, important questions, and previous year solved papers in PDF format. Get free study materials, NCERT solutions, and exam preparation resources for Class 9th Standard CBSE Mathematics

Questions + Answers key

Take MCQ Mathematics Test

QB365 Student Learing Managemnet System

Std: 9th Standard CBSE - Mathematics

chapter: Lines and Angles - Model Questions Papers

Visit QB365-SLMS - https://www.qb365.in/slms/ Complete Questions and Answers

Questions:

Multiple Choice Question

8 x 1 = 8

The angle which is equal to 8 times its compliment is:

(a)

\(80^{ 0 }\)

(b)

\(72^{ 0 }\)

(c)

\(90^{ 0 }\)

(d)

\(88^{ 0 }\)

Which of the following is not a pair of supplementary angles?

(a)

\(90^{ 0 },90^{ 0 }\)

(b)

\(32^{ 0 },58^{ 0 }\)

(c)

\(0^{ 0 },180^{ 0 }\)

(d)

76,\(104^{ 0 }\)

The angle of supplementary to \(90^{ 0 }\)+\(9^{ 0 }\) is

(a)

\(90^{ 0 }\)+\(9^{ 0 }\)

(b)

\(90^{ 0 }\)-\(9^{ 0 }\)

(c)

\(180^{ 0 }\)-+\(9^{ 0 }\)

(d)

\(180^{ 0 }\)-\(9^{ 0 }\)

The compliment of (\(90^{ 0 }\)-\(a^{ 0 }\)) is

(a)

\(-a^{ 0 }\)

(b)

\(90^{ 0 }\)+\(a^{ 0 }\)

(c)

\(90^{ 0 }\)-\(a^{ 0 }\)

(d)

\(a^{ 0 }\)

A straight angle

(a)

is greater than \(90^{ 0 }\) but less than \(180^{ 0 }\)

(b)

is exactly equal to \(90^{ 0 }\)

(c)

measures between \(0^{ 0 }\) and \(90^{ 0 }\)

(d)

is exactly equal to \(180^{ 0 }\)

The sum of two complimentary angles is

(a)

\(180^{ 0 }\)

(b)

\(360^{ 0 }\)

(c)

\(90^{ 0 }\)

(d)

None of these

How many types of angles are formed between the edges of plane surfaces?

(a)

Of different types

(b)

Of only one type

(c)

Of only two types

(d)

of only three types

The minimum number of points required to draw a line is

(a)

(b)

(c)

(d)

Generic 4

2 x 4 = 8

In figure, if y=\(20^{ 0 }\) , prove that the line AOB is a straight line.

10.

Ray OE bisects \(\angle \)AOB and OF the ray opposite to OE Show that \(\angle \)FOB=\(\angle \)FOA

Generic 2

5 x 2 = 10

11.

Let OA,AB, OC and OD by the rays in the anticlockwise direction starting from OA, such that \(\angle AOB=\angle COD=100^{ 0 };\angle AOD=\angle BOC=80^{ 0 }\) Is it true that AOC and BOD are straight lines? Justify your answer by drawing the figures.

12.

find the angles of a triangle PQR if \(\angle p-\angle q=45^{ 0 }\) and \(\angle Q-\angle R=30^{ 0 }\)

13.

In \(\triangle \) ABC if \(\angle A=(2Xx-5)^{ 0 },\angle B=(5X+5)^{ 0 }\) \(\angle C=(3Xx-50)^{ 0 }\) then find the values of x,\(\angle \) A ,\(\angle B\) and \(\angle C.\)

14.

In figure find the value of x.

15.

(a) In the figure , what value of x will make POQ a straight line:

(b)In the given figure find the value of x,If AOB is a line

1 Marks

10 x 1 = 10

16.

In the given figure, what is the value of x?

17.

In the figure below, in \(\triangle ABC,\) AB=AC, then calculate the value of x.

18.

In the figure below, if \(\angle A+\angle B+\angle C+\angle D+\angle E+\angle F=k\) right angles, then what is the value of k?

19.

In \(\triangle ABC,\angle A=\angle B/2=\angle C/6,\) then what will be the measurement of \(\angle A?\)

20.

In the figure below, if x,y and z are exterior angles of \(\triangle ABC\), then calculate the value of x+y+z.

21.

In the given figure, PQ||RS and EF||QS. If \(\angle PQS=60^o\), then what will be the measure of \(\angle RFE?\)

22.

If a transversal intersects two parallel lines, then which of the pairs of angles is equal.

23.

A transversal l intersects two lines m and n such that a pair of alternate interior angles is equal. Then, what can you say about the lines m and n?

24.

Write the complementary angle of 65^o.

25.

What is the measure of an angle which is complement of itself?

Visit QB365-SLMS - https://www.qb365.in/slms/

Answers Key:

Multiple Choice Question

8 x 1 = 8

0=8\((90^{ 0 }-\theta )\)

\(32^{ 0 }+,58^{ 0 }=90^{ 0 }\neq 180^{ 0 }\)

Required angle=\(180^{ 0 }\)-(\(90^{ 0 }\)+\(9^{ 0 }\)) =\(90^{ 0 }\)+\(9^{ 0 }\)

Complement of (\(90^{ 0 }\)-\(a^{ 0 }\))
=\(90^{ 0 }\)-(\(90^{ 0 }\)-\(a^{ 0 }\))=\(a^{ 0 }\)

Definition of straight angle

Definition of complementary angles

(a)
Of different types

(b)
2

Generic 4

2 x 4 = 8

\(\because \) Sum of all the angle round a point is equal to \(360^{ 0 }\)

\(\therefore \) y+(3x-15)+(y+15)+2y+(4y+10)+x=\(360^{ 0 }\)
\(\Rightarrow \) 4x+8y=\(360^{ 0 }\)
\(\Rightarrow \) x+2y=\(90^{ 0 }\)
\(\Rightarrow \) x+2(\(20^{ 0 }\))=\(90^{ 0 }\)
\(\Rightarrow \) x+\(40^{ 0 }\)=\(90^{ 0 }\)
\(\Rightarrow x=50^{ 0 }\)
Now, y+3x-15+y+5=3x+2y-10
= 3(\(50^{ 0 }\))+2(\(20^{ 0 }\))-10
\(=150^{ 0 }+40^{ 0 }-10^{ 0 }\)
= \(180^{ 0 }\)
\(\therefore \) AOB is straight line.

10.

\(\angle \)FOB+\(\angle \)BOE=\(180^{ 0 }\) ...(1)
| Linear pair Axiom
\(\angle \)FOA+\(\angle \)AOE=\(180^{ 0 }\) .. (2)
| Linear Pair Axiom
From (1) and (2)
\(\angle \)FOB+\(\angle \)BOE=\(\angle \) FOA+\(\angle \)AOE ....(3)
But \(\angle \)BOE=\(\angle \)AOE
\(\therefore \) From (3)
\(\Rightarrow \) \(\angle \)FOB=\(\angle \)FOA

Generic 2

5 x 2 = 10

11.

Yes ! AOC and BOD both are straight lines

12.

\(100^{ 0 },55^{ 0 },25^{ 0 }\)

13.

\(13;21^{ 0 },70^{ 0 },89^{ 0 }\)

14.

15.

(a) 28
(b) 26

1 Marks

10 x 1 = 10

16.

()
Here, x+10^o+x+x+20^o=180^o
3x=180^o-30^o=150^o
\(x=\frac{150^o}{3}=50^o\)

17.

()
AB=AC
\(\angle ACB=\angle B\)
In \(\triangle ABC, 80^o+\angle ACB+\angle B\)
=180^o (Prop. of isosceles \(\triangle)\)
\(2\angle ACB=100^o\)
\(\angle ACB=50^o\)
Again, \(\angle ACB+x=180^o\) (Linear pair)
50^o+x=180^o
x=130^o

18.

()
In \(\triangle ABC,\)
\(\angle A+\angle B+\angle C=180^o\)
Also, in \(\triangle DEF,\)
\(\angle D+\angle E+\angle F=180^o\)
\(\therefore \angle A+\angle B+\angle C+\angle D+\angle E+\angle F=360^o\)
=4 X 90^o
Hence,k=4 right angles.

19.

()
In \(\triangle ABC,\)
\(\angle A+\angle B+\angle C=180^o\)(By given conditions)
\(\Rightarrow \angle A+2\angle A+6\angle A=180^o\)
\(\Rightarrow 9\angle A=180^o\)
\(\Rightarrow \angle A=20^o\)

20.

()
Since sum of all the exterior angles formed by producing the sides of a polygon is 360^o
x^o+y^o+z^o=360^o

21.

()
\(\angle PQS+\angle QSF=180^o\) (Angles on the same side of transversal)
\(\Rightarrow\angle PQS+\angle RFE-180^o, as\ \angle QSF=\angle EFR\)
\(\Rightarrow 60^o+\angle RFE=180^o (Corresponding\ \angle S)\)
\(\therefore \angle RFE=120^o\)

22.