How_To_Be_Good_At_Math

216 GEOMETRY • QUADRILATERALS

Quadrilaterals

A quadrilateral is a polygon with four straight

sides, four vertices, and four angles. “Quad”

comes from the Latin word for “four”.

Opposite sides are marked with dashes

to show they are the same length

Sides that are parallel

are marked with the

same arrow symbols

Angles that

are equal are

marked with

curved lines,

called arcs

Parallelogram

A parallelogram has two sets of parallel

sides. Its opposite sides and opposite angles

are equal.

Rhombus

A rhombus has four sides of equal length.

Its opposite sides are parallel, and its opposite

angles are equal.

Rectangle

The opposite sides of a rectangle are the

same length and are parallel to each other.

Each of its four angles is a right angle.

Square

A square has four sides of equal length.

Each of its four angles is a right angle. The

opposite sides of a square are parallel.

Types of quadrilaterals

Here are some of the most common quadrilaterals.

Quadrilaterals always have

straight sides. You can’t have

a curved quadrilateral!

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