What is Trignometry?
Trigonometry is a branch
of mathematics that studies triangles and
the relationships between their sides and
the angles between these sides.
In this topic we shall make use of
 Trignometric Ratios to find the
height of a tree,a tower,a water
tank,width of a river,distance of
    ship from lighthouse etc.
Line of Sight




                Horizontal
Angle of Elevation
  The angle which the line of sight
 makes with a horizontal line drawn
 away from their eyes is called the
angle of Elevation of aeroplane from
                them.
Angel of Elevation



                     Angel of Elevation
Angel of Depression
 If the pilot of the aeroplane looks
 downwards at any object on the
ground then the Angle between his
  line of sight and horizontal line
drawn away from his eyes is called
        Angel of Depression
Angle of Depression


        Horizontal



                      Angel of Depression
Now let us Solve some
  problem related to
 Height and Distance
The angle of elevation of the top of a tower from a
      point on the ground, which is 30 m away from the
    foot of the tower is 30°. Find the height of the tower.
.
Let AB be the tower and the angle of elevation from point C
(on ground) is
30°.
In ΔABC,




     Therefore, the height of the tower is
A circus artist is climbing a 20 m long rope, which is tightly
  stretched and tied from the top of a vertical pole to the
ground. Find the height of the pole, if the angle made by the
               rope with the ground level is 30 °.

Sol:- It can be observed from the figure that AB is the pole.
       In ΔABC,




    Therefore, the height of the pole is 10 m.
.




Let K be the kite and the string is tied to point P on
the ground.
In ΔKLP,




    Hence, the length of the string is
,
.




              Height of tree =   + BC




    Hence, the height of the tree is
Trignometry
Trignometry
Trignometry

Trignometry

  • 2.
    What is Trignometry? Trigonometryis a branch of mathematics that studies triangles and the relationships between their sides and the angles between these sides.
  • 3.
    In this topicwe shall make use of Trignometric Ratios to find the height of a tree,a tower,a water tank,width of a river,distance of ship from lighthouse etc.
  • 5.
    Line of Sight Horizontal
  • 6.
    Angle of Elevation The angle which the line of sight makes with a horizontal line drawn away from their eyes is called the angle of Elevation of aeroplane from them.
  • 7.
    Angel of Elevation Angel of Elevation
  • 8.
    Angel of Depression If the pilot of the aeroplane looks downwards at any object on the ground then the Angle between his line of sight and horizontal line drawn away from his eyes is called Angel of Depression
  • 9.
    Angle of Depression Horizontal Angel of Depression
  • 11.
    Now let usSolve some problem related to Height and Distance
  • 12.
    The angle ofelevation of the top of a tower from a point on the ground, which is 30 m away from the foot of the tower is 30°. Find the height of the tower. . Let AB be the tower and the angle of elevation from point C (on ground) is 30°. In ΔABC, Therefore, the height of the tower is
  • 13.
    A circus artistis climbing a 20 m long rope, which is tightly stretched and tied from the top of a vertical pole to the ground. Find the height of the pole, if the angle made by the rope with the ground level is 30 °. Sol:- It can be observed from the figure that AB is the pole. In ΔABC, Therefore, the height of the pole is 10 m.
  • 14.
    . Let K bethe kite and the string is tied to point P on the ground. In ΔKLP, Hence, the length of the string is
  • 15.
  • 16.
    . Height of tree = + BC Hence, the height of the tree is