EDEXCEL GCSE FOUNDATION MATHS - What are Rotations

EDEXCEL GCSE Foundation Maths - Rotations

What is a Rotation?

A rotation is a transformation that turns a shape around a fixed point called the centre of rotation. The shape is turned by a certain angle of rotation.

Key Terms:

• Centre of rotation: The point around which the shape is rotated.
• Angle of rotation: The amount of turn, measured in degrees.
• Direction of rotation: Clockwise or anticlockwise.

How to Rotate a Shape:

1. Identify the centre of rotation. This is usually marked with a dot.
2. Determine the angle of rotation. This is usually given in degrees.
3. Decide the direction of rotation. This is usually specified as clockwise or anticlockwise.
4. Rotate each point of the shape around the centre of rotation by the given angle.
5. Connect the rotated points to form the image of the shape.

Example:

Let’s say we want to rotate a triangle ABC 90 degrees clockwise about point O.

1. Centre of rotation: O.
2. Angle of rotation: 90 degrees.
3. Direction of rotation: Clockwise.

• Step 1: Place your pencil on point A and turn it 90 degrees clockwise around point O. Mark the new position as A’.
• Step 2: Repeat this process for points B and C, marking the new positions as B’ and C’.
• Step 3: Connect A’, B’, and C’ to form the rotated triangle A’B’C’.

Things to Remember:

• The size and shape of the shape remain the same after a rotation.
• The orientation of the shape changes.
• The distance between each point and the centre of rotation remains the same.

Practice:

• Try rotating various shapes around different centres of rotation and angles.
• Use a ruler and protractor to help you accurately rotate the shapes.
• Practice identifying the centre of rotation, angle of rotation, and direction of rotation from diagrams.

Note:

• You can also use tracing paper to help you visualize the rotation.
• There are many online tools and apps that can help you practice rotations.