Height and Distance - ( Arithmetic Aptitude)

  1. Trigonometry: In a right angledOAB, whereBOA =,
    i. sin= Perpendicular = AB ;
    Hypotenuse OB
    ii. cos= Base = OA ;
    Hypotenuse OB
    iii. tan= Perpendicular = AB ;
    Base OA
    iv. cosec= 1 = OB ;
    sin AB
    v. sec= 1 = OB ;
    cos OA
    vi. cot= 1 = OA ;
    tan AB
  2. Trigonometrical Identities:
    1. sin2+ cos2= 1.
    2. 1 + tan2= sec2.
    3. 1 + cot2= cosec2.
  3. Values of T-ratios:
    (/6)

    30°
    (/4)

    45°
    (/3)

    60°
    (/2)

    90°
    sin 0
    1
    2
    3
    2
    1
    cos 1
    3
    2
    1
    2
    0
    tan 0
    1
    3
    1 3 not defined
  4. Angle of Elevation: Suppose a man from a point O looks up at an object P, placed above the level of his eye. Then, the angle which the line of sight makes with the horizontal through O, is called theangle of elevationof P as seen from O. Angle of elevation of P from O =AOP.
  5. Angle of Depression: Suppose a man from a point O looks down at an object P, placed below the level of his eye, then the angle which the line of sight makes with the horizontal through O, is called theangle of depressionof P as seen from O.