What is Rotation?
Hello, Year 6! Today, we’re going to learn about rotation. Rotation means turning a shape around a fixed point, which we call the centre of rotation. Imagine turning a steering wheel or spinning a top—that’s what rotation is!
Key Rules of Rotation
- Centre of Rotation: This is the point around which the shape rotates. You can choose any point, but common points are the corners of the shape or the origin (0,0) on a grid.
- Angle of Rotation: This tells us how far to turn the shape. We usually measure the angle in degrees (°). Common angles are:
- 90°: A quarter turn.
- 180°: A half turn.
- 270°: Three-quarters of a turn.
- 360°: A full turn.
- Direction of Rotation: We can rotate shapes in two directions:
- Clockwise: Turn to the right, like the hands of a clock.
- Anticlockwise (or Counterclockwise): Turn to the left.
Visualising Rotation
Let’s think about a square. If we rotate it 90° clockwise around its centre, it will still look the same but in a different position.
Examples of Rotation
- Example 1: Rotate the point (2, 3) 90° clockwise around the origin (0, 0).
- New coordinates: (3, -2)
- Example 2: Rotate the triangle ABC, with vertices A(1, 1), B(1, 4), C(4, 1) 180° anticlockwise around the origin.
- New coordinates: A(-1, -1), B(-1, -4), C(-4, -1)
Tips and Tricks
- Use a Grid: When you’re unsure about where a point will go after rotation, drawing it on graph paper can help.
- Count Squares: If rotating on a grid, count how many squares you move to find the new position.
- Practice with Shapes: Draw different shapes and practice rotating them. It makes it easier to understand!
Questions on Rotation
Easy Level Questions
- What does rotation mean?
- What is the centre of rotation?
- How many degrees are in a full rotation?
- What direction do we rotate in a clockwise direction?
- What is 90° clockwise rotation?
- If you rotate a point 180°, what happens to its position?
- Name a common angle used for rotation.
- What does anticlockwise mean?
- Can you rotate a shape around any point?
- What happens to a square when you rotate it 360°?
Medium Level Questions
- Rotate the point (2, 2) 90° clockwise around the origin. What are the new coordinates?
- What is the new position of the point (3, 4) after a 180° rotation?
- If you rotate a triangle 90° anticlockwise, what happens to its orientation?
- Rotate the point (1, -1) 270° clockwise. Where does it land?
- How do you rotate a shape around a point that is not the origin?
- What is the new position of (5, 5) after a 90° rotation?
- If we rotate a shape 180°, how does it compare to its original position?
- Rotate the point (-2, 1) 90° clockwise. What are the new coordinates?
- How many degrees do we need to rotate to get the same position?
- Can you rotate a shape without changing its size? Why or why not?
Hard Level Questions
- Rotate the triangle with vertices A(2, 3), B(5, 3), C(3, 6) 90° anticlockwise around the origin. What are the new coordinates?
- If a rectangle is rotated 180°, how do the corners change?
- What is the new position of the point (-4, 2) after rotating 270° clockwise?
- How does the angle of rotation affect the final position of a shape?
- If you rotate a shape 90°, can you rotate it back to the original position? How?
- Rotate the point (0, 5) 180° around the origin. What are the coordinates?
- If you rotate (3, -2) 90° clockwise, what will be the coordinates?
- Explain how to find the new position of a shape when rotated by 270° anticlockwise.
- How would you describe the movement of a point that has been rotated 90° clockwise?
- What happens to a circle when it undergoes a rotation?
Answers and Explanations
Easy Level Answers
- Turning a shape around a point.
- The point the shape turns around.
- 360°.
- Turning to the right.
- A quarter turn.
- It moves to the opposite position.
- 90°.
- Turning to the left.
- Yes, but it’s easier with certain points.
- It stays in the same place.
Medium Level Answers
- (2, -2).
- (-2, -4).
- It changes direction but keeps the same shape.
- (-1, -3).
- Use the distance from the shape to the point to rotate.
- (5, -5).
- It flips over to the opposite side.
- (1, -2).
- 360°.
- Yes, rotation changes position but not size.
Hard Level Answers
- A'(-3, -2), B'(-3, -5), C'(-6, -3).
- The corners switch places, but the shape stays the same.
- (2, -4).
- Different angles change the final orientation of the shape.
- Yes, by rotating back the same amount.
- (0, -5).
- (-2, 3).
- Count squares from the centre to find the new position.
- It moves in a circular path around the centre.
- It stays the same; every point on the circle moves equally.
I hope you enjoyed learning about rotation! Practice makes perfect, so keep rotating those shapes!