07 - Question bank trigonometry - Class 10 - Maths Class 10 Notes | EduRev

 Page 1


TRIGONOMETRIC RATIO 
 
 1 - In triangle ABC, right-angled at B, AB = 24 cm, BC = 7 cm. Determine: 
      (a) Sin A, Cos A                                           (b) Sin C, Cos C 
 
 
(a) Sin A, Cos A 
Solution: AB = 24 cm, BC = 7 cm, AC = ? 
The value of AC can be calculated by using Pythagoras Theorem: 
 
 
 
(b) Sin C, Cos C 
Solution: 
 
 
 
Page 2


TRIGONOMETRIC RATIO 
 
 1 - In triangle ABC, right-angled at B, AB = 24 cm, BC = 7 cm. Determine: 
      (a) Sin A, Cos A                                           (b) Sin C, Cos C 
 
 
(a) Sin A, Cos A 
Solution: AB = 24 cm, BC = 7 cm, AC = ? 
The value of AC can be calculated by using Pythagoras Theorem: 
 
 
 
(b) Sin C, Cos C 
Solution: 
 
 
 
 
2 - In the given figure, find tan P - cot R. 
 
Solution:  
Value of QR can be calculated by using Pythagoras theorem: 
 
Now; 
 
 
 
3 - If ???? ?? ?? = 
?? ?? evaluate: 
Solution: 
 
This means, b = 7 and p = 8. 
We can calculate h by using Pythagoras theorem; 
  
 
 
Page 3


TRIGONOMETRIC RATIO 
 
 1 - In triangle ABC, right-angled at B, AB = 24 cm, BC = 7 cm. Determine: 
      (a) Sin A, Cos A                                           (b) Sin C, Cos C 
 
 
(a) Sin A, Cos A 
Solution: AB = 24 cm, BC = 7 cm, AC = ? 
The value of AC can be calculated by using Pythagoras Theorem: 
 
 
 
(b) Sin C, Cos C 
Solution: 
 
 
 
 
2 - In the given figure, find tan P - cot R. 
 
Solution:  
Value of QR can be calculated by using Pythagoras theorem: 
 
Now; 
 
 
 
3 - If ???? ?? ?? = 
?? ?? evaluate: 
Solution: 
 
This means, b = 7 and p = 8. 
We can calculate h by using Pythagoras theorem; 
  
 
 
 
 
Solution: 
 
Solution: 
 
 
 
4 - If 3 cot A = 4, check whether  or not. 
Solution:  
3 cot A = 4 means ?????? ?? = 
4
3
= 
?? ?? 
Hence, p = 3 and b = 4. 
We can calculate h by using Pythagoras theorem; 
  
Page 4


TRIGONOMETRIC RATIO 
 
 1 - In triangle ABC, right-angled at B, AB = 24 cm, BC = 7 cm. Determine: 
      (a) Sin A, Cos A                                           (b) Sin C, Cos C 
 
 
(a) Sin A, Cos A 
Solution: AB = 24 cm, BC = 7 cm, AC = ? 
The value of AC can be calculated by using Pythagoras Theorem: 
 
 
 
(b) Sin C, Cos C 
Solution: 
 
 
 
 
2 - In the given figure, find tan P - cot R. 
 
Solution:  
Value of QR can be calculated by using Pythagoras theorem: 
 
Now; 
 
 
 
3 - If ???? ?? ?? = 
?? ?? evaluate: 
Solution: 
 
This means, b = 7 and p = 8. 
We can calculate h by using Pythagoras theorem; 
  
 
 
 
 
Solution: 
 
Solution: 
 
 
 
4 - If 3 cot A = 4, check whether  or not. 
Solution:  
3 cot A = 4 means ?????? ?? = 
4
3
= 
?? ?? 
Hence, p = 3 and b = 4. 
We can calculate h by using Pythagoras theorem; 
  
 
Now; the equation can be checked as follows: 
LHS: 
 
 
RHS: 
 
 
It is clear that LHS = RHS. 
 
 
 
Page 5


TRIGONOMETRIC RATIO 
 
 1 - In triangle ABC, right-angled at B, AB = 24 cm, BC = 7 cm. Determine: 
      (a) Sin A, Cos A                                           (b) Sin C, Cos C 
 
 
(a) Sin A, Cos A 
Solution: AB = 24 cm, BC = 7 cm, AC = ? 
The value of AC can be calculated by using Pythagoras Theorem: 
 
 
 
(b) Sin C, Cos C 
Solution: 
 
 
 
 
2 - In the given figure, find tan P - cot R. 
 
Solution:  
Value of QR can be calculated by using Pythagoras theorem: 
 
Now; 
 
 
 
3 - If ???? ?? ?? = 
?? ?? evaluate: 
Solution: 
 
This means, b = 7 and p = 8. 
We can calculate h by using Pythagoras theorem; 
  
 
 
 
 
Solution: 
 
Solution: 
 
 
 
4 - If 3 cot A = 4, check whether  or not. 
Solution:  
3 cot A = 4 means ?????? ?? = 
4
3
= 
?? ?? 
Hence, p = 3 and b = 4. 
We can calculate h by using Pythagoras theorem; 
  
 
Now; the equation can be checked as follows: 
LHS: 
 
 
RHS: 
 
 
It is clear that LHS = RHS. 
 
 
 
TRIGONOMETRIC RATIOS OF SOME SPECIFIC ANGLES 
5- Evaluate the following: 
 
Solution: 
  
 
Solution: 
  
6 - Choose the correct option and justify your choice: 
 
Solution: