Question:
If three angles of a quadrilateral are each equal to 75o, the fourth angle is
(a) 150o
(b) 135o
(c) 45o
(d) 75o
Solution:
(b) 135o
We know that, sum of interior angles of quadrilateral is equal to 360o.
From the question it is given that, three angles of a quadrilateral are each equal to 75o.
Let us assume the fourth angle be x.
Then, 75o + 75o + 75o + x = 360o
225 + x = 360o
x = 360o – 225
x = 135o