Vidaara.orgClass 9 · Mathematics
CodeVID-M09-25-CMP-01
Complementary Angles - 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.
$\sin(90^\circ-\theta)=$
- A.$\sin\theta$
- B.$\cos\theta$
- C.$\tan\theta$
- D.$\cot\theta$
2.
$\cos(90^\circ-\theta)=$
- A.$\sin\theta$
- B.$\cos\theta$
- C.$\tan\theta$
- D.$\sec\theta$
3.
$\tan(90^\circ-\theta)=$
- A.$\tan\theta$
- B.$\cot\theta$
- C.$\sin\theta$
- D.$\sec\theta$
4.
$\sec(90^\circ-\theta)=$
- A.$\sec\theta$
- B.$\operatorname{cosec}\theta$
- C.$\cos\theta$
- D.$\tan\theta$
5.
$\sin 60^\circ=$
- A.$\sin 30^\circ$
- B.$\cos 30^\circ$
- C.$\tan 30^\circ$
- D.$\cos 60^\circ$
Section B — Short Answer (2 marks)
4 × 2 = 8 marks
6.
Express $\sin 70^\circ$ as a cosine.
7.
Express $\cos 40^\circ$ as a sine.
8.
Express $\tan 55^\circ$ as a cotangent.
9.
Evaluate $\sin 30^\circ-\cos 60^\circ$.
Section C — Short Answer (3 marks)
4 × 3 = 12 marks
10.
Evaluate $\dfrac{\sin 35^\circ}{\cos 55^\circ}$.
11.
Evaluate $\cos 48^\circ-\sin 42^\circ$.
12.
Simplify $\tan 20^\circ\cdot\tan 70^\circ$.
13.
Evaluate $\dfrac{\sec 50^\circ}{\operatorname{cosec} 40^\circ}$.
Section D — Long Answer (5 marks)
2 × 5 = 10 marks
14.
Without tables, evaluate $\dfrac{\sin 25^\circ}{\cos 65^\circ}+\dfrac{\cos 25^\circ}{\sin 65^\circ}$.
15.
Show that $\sin 48^\circ\sec 42^\circ+\cos 48^\circ\operatorname{cosec} 42^\circ=2$.
Answer Key
Section A — Multiple Choice Questions
- (B) $\cos\theta$
- (A) $\sin\theta$
- (B) $\cot\theta$
- (B) $\operatorname{cosec}\theta$
- (B) $\cos 30^\circ$
Section B — Short Answer (2 marks)
- $\cos 20^\circ$.
- $\sin 50^\circ$.
- $\cot 35^\circ$.
- $0$.
Section C — Short Answer (3 marks)
- $1$.
- $0$.
- $1$.
- $1$.
Section D — Long Answer (5 marks)
- $2$.
- $=2$.
Generated by Vidaara.org · Assignment VID-M09-25-CMP-01 · vidaara.org