What is the dynamic view of angle?

An angle is a measurement. When we talk about the angle between two lines we are not referring to the shape formed by the two lines, nor to the point where they meet, nor to the space between the lines, but to a particular kind of measurement.

There are two ways we can think of what it is that is being measured. First, there is the dynamic view of angle: the angle between the lines is a measurement of the size of the rotation involved when you point along one line and then turn to point along the other. This is the most useful way of introducing the concept of angle to children, because it lends itself to practical experience, with the children themselves pointing in one direction and then turning themselves through various angles to point in other directions. Also, when it comes to measuring angles between lines drawn on paper, pupils can physically point to something, such as a pencil or a finger, along one line and rotate about the intersection of the lines to point along the other line.

We should note that there are always two angles involved when turning from one direction to another, depending on whether you choose to rotate clockwise or anticlockwise.