Trapezoids
(KS2, Year 6)

The Lesson

A trapezoid is a four sided shape with one pair of opposite parallel sides.

Parts of a Trapezoid

• The parallel sides of a trapezoid are called bases.
  
  
• The other sides of a trapezoid are called legs or lateral sides.
  
  

Properties of Trapezoids

• Only one pair of sides of a trapezoid is parallel.
  
  The other pair of sides is not parallel.

The Perimeter of a Trapezoid

The perimeter of a trapezoid is given by the formula:

In this formula, b₁ and b₂ are the lengths of the bases of the trapezoid and l₁ and l₂ are the lengths of the legs of the trapezoid.

The Area of a Trapezoid

The area of a trapezoid is given by the formula:

In this formula, b₁ and b₂ are the lengths of the bases of the trapezoid and h is the height of the trapezoid.
Read more about how to find the area of a trapezoid

Interactive Widget

Here is an interactive widget to help you learn about trapezoids.

Trapezoid, Trapezium

The shape is called a trapezoid in North America. In English speaking countries outside North America, a trapezoid is called a trapezium.

What's in a Name?

Trapezoid and trapezium come from the Greek word "trapezion" meaning 'little table'.

A Trapezoid is a Polygon

A trapezoid is a type of polygon. A polygon is a 2-dimensional shape with straight sides. A trapezoid is an irregular polygon. Irregular polygons have different length sides and different angles.

A Trapezoid is a Quadrilateral

A trapezoid is a quadrilateral. A trapezoid is a four-sided polygon. Parallelograms, rectangles and squares are also quadrilaterals.

See Also

Finding the area of a trapezoid What is a polygon? Learn about trapezoids ( interactive widget)