Geometry

Assuming Every Quadrilateral with Equal Sides Is a Square

Students see four equal side lengths and call the quadrilateral a square.

Quick check

Why students make it

Equal sides are a very noticeable feature of a square. Students may forget that angle measures matter too.

The rule done right

A quadrilateral with four equal sides is a rhombus. It is a square only if it also has four right angles, so each angle must be 90∘90^\circ.

Related resources

quadrilateralsrhombussquares