What is a trapezoid? Geometry made simple

You can find an explanation of what a trapezoid is in the area of geometry. You have certainly come across the term « trapezium » here before, without perhaps being able to directly imagine something concrete behind it. However, the properties of a trapezoid can be easily summarised.

What a trapezoid actually is

Every geometric solid has special properties that it must fulfil in order to be identified as such.

• A trapezoid is generally a quadrilateral that has two parallel sides. These are also called basic sides.

• A trapezoid has four corners and four sides, also called a, b, c and d.

• The four corner angles of the trapezoid add up to 360°. These are also called α, β, γ and δ.

• The length of the legs of a trapezoid is not fixed. They can also be of different lengths.

• There are different forms of the trapezoid. A distinction is made between an isosceles trapezium and a right-angled trapezium.

Calculations around the trapezoid

If you want to do certain calculations around the trapezoid, it is important to know the appropriate formulae.

• Calculate the area like this: A= ½ × (a+c) × h

• Calculate the perimeter like this: U= a + b + c + d