5. A quadrilateral with all four sides equal is either a square or a rhombus. If the angles are not 90° it is a rhombus. There are other types of quadrilaterals as well.

Quadrilaterals
NAME
SHAPE
DEFINITION
square

all sides equal, all angles 90°
rectangle

opposite sides equal, all angles 90°
parallelogram

opposite sides equal, opposite sides parallel
rhombus

all sides equal, opposite sides parallel
kite

two pairs of adjacent equal sides
trapezoid

one pair of opposite parallel sides
isosceles trapezoid

one pair of opposite parallel sides, other pair equal