Question

In a square $ABCD$, the diagonals bisect at $O$. What type of a triangle of $△AOB$?

• A. An equilateral triangle
• B. An isosceles but not a right angles triangle
• C. A right angles but not an isosceles triangle
• D. An isosceles right angled triangle

Answer 1

The correct option is D An isosceles right angled triangle

As all diagonals of squares are of equal length

$\Rightarrow \angle OAB=\angle OBA=\angle OBC=\angle OCB=\angle OCD=\angle ODC=\angle OPA=\angle OAD={45}^{\circ }$

$\angle AOB={90}^{\circ }$ and $OA=OB$

Hence, $\Delta AOB$ is a right angle isosceles triangle.