1. Transformations and its Types
Transformations change a shape in the coordinate grid by rotation, reflection, or translation of the shape.
In 11 plus exams, you need to identify and transform the shapes in a coordinate grid, so let us begin by exploring the three types of transformations.
1.1 What is Rotation?
A rotation is when a shape is turned or spun around a fixed point. You need to know three things in order to rotate a shape on the graph:
- Point of rotation
- The direction of rotation (clockwise, anticlockwise)
- Degree of rotation
1.2 Rotation on Graph Example
Look at the example below:
Transformations: a) Shape A is transformed to shape B by rotation of 90 degrees
clockwise about the origin.
b) Shape A is transformed to shape C by rotation of 180 degrees
anticlockwise about the origin.
2.What is Reflection?
A reflection is when a shape is reflected or flipped in a mirror line. A reflection doesn’t change the size of the shape. After reflection, point and the reflected point are at the same distance from the mirror line.
2.1 Reflection on Graph Example
Observe the reflection shown below:
Transformation: a) Shape A is reflected in the mirror line to get shape B.
b) Points on shapes A and B are at the same distance from the mirror
line.
3. What is Translation?
A translation is when a shape is moved up, down, right, or left without being flipped or rotated. The size of the shape remains the same after translation. In order to translate a shape, each point must move the same distance from the origin.
3.1 Translation on graph example
Let us see how to translate a shape on the coordinate grid.
Transformation: a) Shape A has been transformed to shape B by translating it 6 units right and 7 units down.
b) You can notice from the above transformation that after translation, the
new shape looks exactly similar to the original shape.
