All the angles of a quadrilateral are equal. What special name is given to this quadrilateral?
We know that, sum of all angles in a quadrilateral is 360°.
If ABCD is a quadrilateral,
∠A+ ∠B+ ∠C + ∠D = 360° …(i)
But it is given all angles are equal.
∠A = ∠B = ∠C = ∠D From Eq. (i)
∠A + ∠A + ∠A + ∠A = 360°
=> 4 ∠A = 360°
∠A = 90°
So, all angles of a quadrilateral are 90°.
Hence, given quadrilateral is a rectangle.