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Vidaara.orgClass 8 · Mathematics
CodeVID-M08-09-CSU-01
Complementary & Supplementary Angles - Assignment
Chapter: Basic Geometry
Topic: Pairs of Angles: Complementary & Supplementary
Maximum Marks: 35
Time: 75 minutes
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.
Complementary angles sum to:
  • A.$90^\circ$
  • B.$180^\circ$
  • C.$360^\circ$
  • D.$45^\circ$
2.
Supplementary angles sum to:
  • A.$90^\circ$
  • B.$180^\circ$
  • C.$360^\circ$
  • D.$270^\circ$
3.
The complement of $40^\circ$ is:
  • A.$40^\circ$
  • B.$50^\circ$
  • C.$140^\circ$
  • D.$60^\circ$
4.
The supplement of $110^\circ$ is:
  • A.$70^\circ$
  • B.$80^\circ$
  • C.$90^\circ$
  • D.$110^\circ$
5.
Two equal complementary angles are each:
  • A.$30^\circ$
  • B.$45^\circ$
  • C.$60^\circ$
  • D.$90^\circ$
Section B — Short Answer (2 marks) 4 × 2 = 8 marks
6.
Find the complement of $35^\circ$.
7.
Find the supplement of $100^\circ$.
8.
Two complementary angles are equal. Find each.
9.
Find the supplement of $90^\circ$.
Section C — Short Answer (3 marks) 4 × 3 = 12 marks
10.
The complement of an angle is $25^\circ$. Find the angle.
11.
The supplement of an angle is $140^\circ$. Find the angle.
12.
Two supplementary angles are in the ratio $2:3$. Find them.
13.
An angle is $20^\circ$ more than its complement. Find the angle.
Section D — Long Answer (5 marks) 2 × 5 = 10 marks
14.
Two complementary angles are in the ratio $4:5$. Find both angles.
15.
An angle is three times its supplement. Find the angle and its supplement.

Answer Key

Section A — Multiple Choice Questions
  1. (A) $90^\circ$
  2. (B) $180^\circ$
  3. (B) $50^\circ$
  4. (A) $70^\circ$
  5. (B) $45^\circ$
Section B — Short Answer (2 marks)
  1. $55^\circ$.
  2. $80^\circ$.
  3. $45^\circ$.
  4. $90^\circ$.
Section C — Short Answer (3 marks)
  1. $65^\circ$.
  2. $40^\circ$.
  3. $72^\circ$ and $108^\circ$.
  4. $55^\circ$.
Section D — Long Answer (5 marks)
  1. $40^\circ$ and $50^\circ$.
  2. $135^\circ$ and $45^\circ$.
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