Three angles of a quadrilateral are in the ratio 3 : 4 : 5 : 6. The smallest of these angles is

Let the angles be 3x, 4x, 5x and 6x

3x + 4x + 5x + 6x = 360o (Sum of angles of a quadrilateral)


18x = 360o


x =


x = 20o


Angles of the quadrilateral are:


3x = 3 × 20o = 60o


4x = 4 × 20o = 80o


5x = 5 × 20o = 100o


6x = 6 × 20o = 120o


Hence, the smallest angle is 60o


Option (B) is correct

2