Question:
The angles of a quadrilateral are in the ratio 1 : 2 : 3 : 4. The smallest angle is
(a) 72o
(b) 144o
(c) 36o
(d) 18o
Solution:
(c) 36o
We know that, sum of all interior angle of quadrilaterals is equal to 360o.
Let us assume the angles be x, 2x, 3x, and 4x
Then,
x + 2x + 3x + 4x = 360o
10x = 360o
x = 360/10
x = 36
Therefore the angles are x = 36o
2x = 2 × 36 = 72o
3x = 3 × 36 = 108o
4x = 4 × 36 = 144o