Can all the four angles of a quadrilateral be obtuse angles? Give reason for your answer.
Answer: False
Solution.
An obtuse angle is an angle greater than
Let all angles of a quadrilateral be obtuse angles. Now, the smallest obtuse angle will be equal to
Hence the sum of all angles
So we can conclude that, if all the angles are greater than 90o the sum of all the angles will be greater than
But we know that sum of all the angles in a quadrilateral is .
Therefore, a quadrilateral can have a maximum of three obtuse angles.
Hence given statement is False.