EduSahara™ Worksheet
Name : Chapter Based Worksheet
Chapter : Trigonometrical Identities
Grade : ICSE Grade X
License : Non Commercial Use
Question 1
1.
In the given figure, △DFE is right angled at E. If DE = 13 cm and ∠F = 45°, find DF
  • (i)
    26
    cm
  • (ii)
    13

    2



    12
    cm
  • (iii)
    13
    cm
  • (iv)
    13



    2
    cm
  • (v)
    26



    3
    cm
Question 2
2.
    • The value of
    • tan
      258°
    • in terms of an angle between
    • and
    • 90°
    • is
  • (i)
    cot
    78°
  • (ii)
    tan
    78°
  • (iii)
       
    tan
    78°
  • (iv)
       
    cot
    78°
Question 3
3.
    • Given
    •  
    • sec
      N
    • =
    • 2

      3



      3
    • ,
    • find
    •  
    • cot
      N
  • (i)
    1

    3



    3
  • (ii)



    3
  • (iii)
    1

    2
  • (iv)
    1

    2



    3
  • (v)
    2
Question 4
4.
In the given figure, △FGH is a right angle triangle with ∠H = 90° and GH = 14 cm. R is the mid-point of FH. Find RH
  • (i)
    7

    2



    2
    cm
  • (ii)
    7

    3



    18
    cm
  • (iii)
    7

    3
    cm
  • (iv)
    7

    3



    3
    cm
  • (v)
    7
    cm
Question 5
5.
    • Given
    •  
    • cot
      A
    • =
    • 12

      5
    • ,
    • find
    •  
    • cosec
      A
  • (i)
    12

    13
  • (ii)
    5

    13
  • (iii)
    13

    12
  • (iv)
    13

    5
  • (v)
    5

    12
Question 6
6.
    • Express
    •  
    • cosec
      θ
    •  
    • in terms of
    •  
    • cot
      θ
  • (i)
     
     
    cot
    θ

     
     

    1
      +  
    cot
    2
     
    θ
  • (ii)
     
     
    1

     
     
    cot
    θ
  • (iii)
     
     
    1

     
     

    1
      +  
    cot
    2
     
    θ
  • (iv)
     
     

    1
      +  
    cot
    2
     
    θ
  • (v)
     
     

    1
      +  
    cot
    2
     
    θ

     
     
    cot
    θ
Question 7
7.
    • cos
      (
      A
        +  
      B
      )
    • =
  • (i)
     
     
    cos
    A
    cos
    B
       
    sin
    A
    sin
    B
  • (ii)
     
     
    sin
    A
    cos
    B
      +  
    cos
    A
    sin
    B
  • (iii)
     
     
    cos
    A
    cos
    B
      +  
    sin
    A
    sin
    B
  • (iv)
     
     
    sin
    A
    cos
    B
       
    cos
    A
    sin
    B
Question 8
8.
    • In the given figure,
    • sec
      D
    • =
  • (i)
    DC

    DB
  • (ii)
    EC

    ED
  • (iii)
    BC

    BD
  • (iv)
    BD

    CD
  • (v)
    CB

    CD
Question 9
9.
    • Given
    •  
    • cot
      B
    • =
    • 2



      2
    • ,
    • find
    •  
    • sec
      B
  • (i)
    1

    4



    2
  • (ii)
    1

    3
  • (iii)
    2

    3



    2
  • (iv)
    3

    4



    2
  • (v)
    3
Question 10
10.
Which of the following are true?
a)
 
 
1
  +  
sin
θ

 
 
cos
θ
  +  
 
 
cos
θ

 
 
1
  +  
sin
θ
 = 
 
 
2
sec
θ
b)
 
 
cos
θ

 
 
cosec
θ
  +  
1
  +  
 
 
cos
θ

 
 
cosec
θ
   
1
 = 
 
 
2
tan
θ
c)
 
 
(
sec
θ
   
tan
θ
)
2
 = 
 
 
1
  +  
sin
θ

 
 
1
   
sin
θ
d)
 
 
(
sec
θ
   
tan
θ
)
2
 = 
 
 
1
   
sin
θ

 
 
1
  +  
sin
θ
e)
 
 
cos
θ

 
 
1
   
sin
θ
  +  
 
 
cos
θ

 
 
1
  +  
sin
θ
 = 
 
 
2
  • (i)
    {e,b}
  • (ii)
    {c,e,d}
  • (iii)
    {c,a,b}
  • (iv)
    {c,a}
  • (v)
    {a,b,d}
Question 11
11.
In the given figure, △DFE is right angled at E. If DE = 24 cm and ∠F = 60°, find EF
  • (i)
    24
    cm
  • (ii)
    8



    3
    cm
  • (iii)
    8
    cm
  • (iv)
    12



    2
    cm
  • (v)
    8



    18
    cm
Question 12
12.
    • Given
    •  
    • sin
      E
    • =
    • 4

      5
    • ,
    • find
    •  
    • cosec
      E
  • (i)
    5

    4
  • (ii)
    3

    4
  • (iii)
    3

    5
  • (iv)
    5

    3
  • (v)
    4

    3
Question 13
13.
    • The value of
    • sec
      133°
    • in terms of an angle between
    • and
    • 90°
    • is
  • (i)
       
    sec
    43°
  • (ii)
    sec
    43°
  • (iii)
    cosec
    43°
  • (iv)
       
    cosec
    43°
Question 14
14.
In the given figure, △ACB is right angled at B. If AB = 8 cm and ∠C = 30°, find AD
  • (i)
    1
    cm
  • (ii)
    4
    cm
  • (iii)
    3
    cm
  • (iv)
    5
    cm
  • (v)
    7
    cm
Question 15
15.
Find the length of the side of a 6-sided regular polygon inscribed in a circle of radius 1 m
  • (i)
    1.0500 m
  • (ii)
    1.0000 m
  • (iii)
    1.1000 m
  • (iv)
    0.9000 m
Question 16
16.
For angle values from 0° to 90°, which of the following are true?
a)
The product of the sine and cosine values remains a constant
b)
The cotangent value of the angle increases
c)
The sum of the squares of the sine and cosine values remains a constant
d)
The tangent value of the angle increases
e)
The cosine value of the angle increases
f)
The sine value of the angle increases
  • (i)
    {a,c}
  • (ii)
    {b,d}
  • (iii)
    {b,c,d}
  • (iv)
    {e,a,f}
  • (v)
    {c,d,f}
Question 17
17.
    • Express
    •  
    • sin
      35°
    •  
    • in terms of
    •  
    • cot
      35°
  • (i)
     
     
    cot
    35°

     
     

    1
      +  
    cot
    2
     
    35°
  • (ii)
     
     

    1
      +  
    cot
    2
     
    35°

     
     
    cot
    35°
  • (iii)
     
     
    1

     
     
    cot
    35°
  • (iv)
     
     

    1
      +  
    cot
    2
     
    35°
  • (v)
     
     
    1

     
     

    1
      +  
    cot
    2
     
    35°
Question 18
18.
    • Given
    •  
    • cos
      F
    • =
    • 4

      7



      3
    • ,
    • find
    •  
    • cot
      F
  • (i)
    7

    12



    3
  • (ii)
    4



    3
  • (iii)
    1

    7
  • (iv)
    7
  • (v)
    1

    12



    3
Question 19
19.
In the given figure, △EFG is a right angle triangle with ∠G = 90° and FG = 13 cm. R is the mid-point of EG. Find ∠RFE using tables.
  • (i)
    16 °   7 '  
  • (ii)
    19 °   7 '  
  • (iii)
    21 °   7 '  
  • (iv)
    22 °   7 '  
  • (v)
    17 °   7 '  
Question 20
20.
    • sec
      59°
      cosec
      71°

      cosec
      31°
      sec
      19°
    • =
  • (i)
    0
  • (ii)
    tan
    71°
  • (iii)
    -1
  • (iv)
    1
  • (v)
    tan
    59°
Question 21
21.
    • The value of
    • sec
      79°
    • in terms of an angle between
    • and
    • 90°
    • is
  • (i)
    sec
    79°
  • (ii)
    cosec
    79°
  • (iii)
       
    cosec
    79°
  • (iv)
       
    sec
    79°
Question 22
22.
    • The value of
    • cosec
      45°
    • in terms of an angle between
    • and
    • 90°
    • is
  • (i)
       
    sec
    45°
  • (ii)
    cosec
    45°
  • (iii)
       
    cosec
    45°
  • (iv)
    sec
    45°
Question 23
23.
Which of the following are true?
a)
    • sec
      (
      90
         
      θ
      )
    • =
    • cosec
      θ
b)
    • cos
      (
      90
         
      θ
      )
    • =
    • cos
      θ
c)
    • cosec
      (
      90
         
      θ
      )
    • =
    • sec
      θ
d)
    • cos
      (
      90
         
      θ
      )
    • =
    • cot
      θ
e)
    • cot
      (
      90
         
      θ
      )
    • =
    • tan
      θ
f)
    • tan
      (
      90
         
      θ
      )
    • =
    •    
      tan
      θ
  • (i)
    {a,c,e}
  • (ii)
    {d,c}
  • (iii)
    {b,a}
  • (iv)
    {f,b,e}
  • (v)
    {d,a,c}
Question 24
24.
    • Express
    •  
    • tan
      θ
    •  
    • in terms of
    •  
    • sin
      θ
  • (i)
     
     
    sin
    θ

     
     

    1
       
    sin
    2
     
    θ
  • (ii)
     
     

    1
       
    sin
    2
     
    θ

     
     
    sin
    θ
  • (iii)
     
     
    1

     
     
    sin
    θ
  • (iv)
     
     
    1

     
     

    1
       
    sin
    2
     
    θ
  • (v)
     
     

    1
       
    sin
    2
     
    θ
Question 25
25.
In the given figure, △BDC is right angled at C. If BC = 15 cm and ∠D = 45°, find BE
  • (i)
    15

    4



    12
    cm
  • (ii)
    15

    2
    cm
  • (iii)
    15

    2



    2
    cm
  • (iv)
    15



    3
    cm
  • (v)
    15
    cm
    Assignment Key

  •  1) (iv)
  •  2) (ii)
  •  3) (ii)
  •  4) (iv)
  •  5) (iv)
  •  6) (iv)
  •  7) (i)
  •  8) (iv)
  •  9) (iv)
  •  10) (v)
  •  11) (ii)
  •  12) (i)
  •  13) (iv)
  •  14) (ii)
  •  15) (ii)
  •  16) (v)
  •  17) (v)
  •  18) (ii)
  •  19) (ii)
  •  20) (iv)
  •  21) (i)
  •  22) (ii)
  •  23) (i)
  •  24) (i)
  •  25) (iii)