2D-shapes

• Wiskunde
• Middelbare school
• havo
• Leerjaar 1

What is the name of the red shape shown before?

1. Rectangle
2. Triangle
3. Circle
4. Pentagon

2D-shapes

Shapes have vertices
(shown as the blue dots in the figure)
and
Shapes have sides
(the line segments between the vertices)

2D-shapes

A 2D-shape with 3 vertices and 3 sides is
called a triangle.
On the right you see triangle ABC,
named after the vertices A, B and C.

2D-shapes

If a 2D-shape has 4 vertices and 4 sides, we call it a quadrilateral. The most known quadrilateral is the square. But there are many others, as you will learn soon!

All shapes above are quadrilaterals

Quadrilaterals

We are going to categorize the quadrilaterals based on the following properties:

• Parallel sides
  
• angles
• length of sides

Tekst

Trapezium

The first special quadrilateral is
the trapezium.
It has 1 pair of parallel sides.
As indicated by the red sides in the figures.

How many vertices does a quadrilateral have?

1. 3
2. 4
3. 5
4. 6

How many sides does a triangle have?

1. 3
2. 4
3. 5
4. 6

Which property does a trapezium have?

1. 1 pair of parallel sides
2. 2 pairs of parallel sides
3. Equal angles
4. Equal sides