Mathematics

Problem

A student asserts, “If all four sides of a quadrilateral are equal, then each interior angle must be

90^{\circ}

.” Which of the following quadrilaterals disproves this assertion? a) A rectangle with adjacent sides

4\,\text{cm}

and

6\,\text{cm}

. b) A rhombus with side

5\,\text{cm}

and one interior angle

60^{\circ}

. c) A square with side

4\,\text{cm}

. d) A kite with sides

5\,\text{cm},\,5\,\text{cm},\,4\,\text{cm},\,4\,\text{cm}