An angle is a measure of turn. When we talk about the angle between two lines, we are not referring to the shape formed by the two lines, not to the point where the lines meet, nor to the space between the lines, but to the size of the rotation involved when you point along one line and then turn to point along the other.
There are always two angles involved when turning from one direction to another: clockwise and anticlockwise.
The equivalent to making measurements of length, mass and capacity using non-standard units is to measure angles in turns and fractions of a turn. A whole turn occurs when you point in one direction, then rotate on the spot until you point again in the same direction.
A quarter turn is called a right angle because it is an ‘upright angle’. A half turn, formed by two straight lines pointing in opposite directions, is sometimes called a straight angle.
Adult learners should be able to describe and make whole, half and quarter turns, clockwise and anticlockwise. They should know that a quarter turn is called a right angle and be able to identify right angles in shapes and patterns, and in the environment. They should know that angles are measured in degrees and that a right angle is 90 degrees. They should recognise that a straight line is equivalent to two right angles.
Learners should also be able to use mathematical language to describe position, direction and movement, e.g. when they give instructions to a friend on how to get to where they live.