Vidaara.orgClass 9 · Mathematics
CodeVID-M09-06-ANG-01
Angle Pairs — Assignment
Name: ____________________
Roll No.: __________
Date: ____________
General Instructions
- All questions are compulsory.
- Section A carries 1 mark each, Section B 2 marks, Section C 3 marks and Section D 5 marks.
- Show all working for Sections B, C and D. Only final answers are given at the end — for full solutions, raise your doubts with your teacher.
Section A — Multiple Choice Questions
5 × 1 = 5 marks
1.
Angles summing to $90^\circ$ are:
- A.supplementary
- B.complementary
- C.vertical
- D.linear
2.
Angles summing to $180^\circ$ are:
- A.complementary
- B.supplementary
- C.equal
- D.right
3.
Vertically opposite angles are:
- A.supplementary
- B.equal
- C.complementary
- D.unequal
4.
A linear pair sums to:
- A.$90^\circ$
- B.$180^\circ$
- C.$360^\circ$
- D.$45^\circ$
5.
Two adjacent angles on a straight line form a:
- A.right angle
- B.linear pair
- C.vertical pair
- D.reflex angle
Section B — Short Answer (2 marks)
4 × 2 = 8 marks
6.
Find the complement of $40^\circ$.
7.
Find the supplement of $110^\circ$.
8.
Two lines intersect; one angle is $70^\circ$. Find the vertically opposite angle.
9.
The angles of a linear pair are $2x$ and $3x$. Find $x$.
Section C — Short Answer (3 marks)
4 × 3 = 12 marks
10.
Two complementary angles are such that one is twice the other. Find them.
11.
Two supplementary angles are in ratio $2:3$. Find them.
12.
If one angle of a linear pair is $65^\circ$, find the other.
13.
Two lines intersect; adjacent angles are $4x$ and $5x$. Find $x$.
Section D — Long Answer (5 marks)
2 × 5 = 10 marks
14.
Lines $AB$ and $CD$ intersect at $O$. If $\angle AOC=50^\circ$, find the other three angles.
15.
The supplement of an angle is three times its complement. Find the angle.
Answer Key
Section A — Multiple Choice Questions
- (B) complementary
- (B) supplementary
- (B) equal
- (B) $180^\circ$
- (B) linear pair
Section B — Short Answer (2 marks)
- $50^\circ$.
- $70^\circ$.
- $70^\circ$.
- $36^\circ$.
Section C — Short Answer (3 marks)
- $30^\circ$ and $60^\circ$.
- $72^\circ$ and $108^\circ$.
- $115^\circ$.
- $x=20^\circ$.
Section D — Long Answer (5 marks)
- $\angle BOD=50^\circ$, $\angle AOD=\angle BOC=130^\circ$.
- $45^\circ$.
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