Express each of the following angles in radians:
(i) –220o (ii) 7o30’ (iii) –(22o30’) (iv) 400o (v) 36o
2. Find the length of an arc of a circle of radius 14 cm which subtends an angle of 36o at the centre.
3. The radius of a circle is 30 cm. Find the length of the arc of this circle whose corresponding chord &
measures 30 cm.
4. A rail road curve is to be raid out on a circle. What radius should be used if the track is to change the
direction by 25o in a distance of 40 metres?
5. Prove that cosθ tanθ + 2 2tanθ + 1 = 2secθ + 5sinθ   
6. Prove that sin -420o cos390o +cos -660o sin330o = -1.    
7. Prove that cos n + 2 x.cos n +1 x + sin n + 2 x.sin n +1 x = cosx        
8.
cos9o +sin9o = tan54o
cos9o -sin9o

9. If tan
1
m
A
m


and

1
tan ,
2 1
B
m


then prove that .
4
A B 
 

10. Prove that:

2 2
2 2
tan 2 tan tan 3 tan
1 tan 2 tan
 

 







EXERCISE - 2

Long Answer Questions
1. Express each of the following angels in degrees:

(i)
5
12
c
  
    (ii) 7
8
c
  
    (iii) 4
c
 (iv)
1
4
c
      (v)  2
c


2. Find the degree measure of the angle subtended at the centre of a circle of radius 100 cm by an arc of
length 22 cm. (Use =
22
7
).

3. A horse is tied to a post by a rope. If the horse moves a circular path always keeping the rope tight and
describes 88 metres when it has traced out 72o at the centre, find the length of the rope.
4. A train is moving on a circular curve of radius 1500 m at the rate of 66 km/hour. Through what angle has
it turned in 10 seconds?