All the angles of a quadrilateral are equal. What special name is given to this quadrilateral ?

Explanation

We know that, sum of all angles in a quadrilateral is `360^(@)`.
If ABCD is a quadrilateral,
`angleA+angleB+angleC+angleD=360^(@)" "...(i)`
But it is given all angles are equal.
`therefore" "angleA=angleB=angleC=angleD`
From Eq. (i), `angleA+angleA+angleA+angleA=360^(@)`
`rArr" "4angleA=360^(@)`
`therefore" "angleA=90^(@)`
So, all angles of a quadrilateral are `90^(@)`.
Hence, given quadrilateral is a rectangle.