1. Year 9 Enlargement Dr J Frost (jfrost@tiffin.kingston.sch.uk) Last modified: 2 nd November 2014

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3. x-5-4-3-2-10123456 y 4 3 2 1 -2 -3 -4 Object Image A Image B Image C Describe the transformations that resulted in the 3 images. (If you finish, can you describe the transformation resulting in Image A using only reflections?) Starter

4. x-5-4-3-2-10123456 y 4 3 2 1 -2 -3 -4 Object Image It’s becoming 2 times as wide. It’s becoming 4 times in size in terms of area. It’s being enlarged about some point. Click to Start Bromanimation Clearly this shape is being ‘enlarged’ in some way. What two things might describe such a transformation? Describing an Enlargement

5. x-5-4-3-2-10123456 y 4 3 2 1 -2 -3 -4 Object Image...by a scale factor of 2. An enlargement about the point (-5, -1) Describing an Enlargement

6. x-5-4-3-2-10123456 y 4 3 2 1 -2 -3 -4 A The centre of enlargement. The distance from the centre is being tripled, so we have enlargement by a scale factor of 3. “Enlargement about the point (-3, 1) by a scale factor of 3.” B Example 1 Describe enlargement from A to B.

7. x-5-4-3-2-10123456 y 4 3 2 1 -2 -3 -4 Describe enlargement from A to B. Example 2 B A

8. x-5-4-3-2-10123456 y 4 3 2 1 -2 -3 -4 Describe enlargement from A to B. Test Your Understanding B A

9. x-5-4-3-2-10123456 y 4 3 2 1 -2 -3 -4 Object Enlarge the shape by a scale factor of 2 about the point (0,-2) Drawing an Enlargement Image The approach is to take each vertex on the object one at a time, count the squares across and up/down from the centre, and times each by the scale factor

10. x-5-4-3-2-10123456 y 4 3 2 1 -2 -3 -4 Object Example 4 Image

11. x-5-4-3-2-10123456 y 4 3 2 1 -2 -3 -4 Object Test Your Understanding Image

12. x-5-4-3-2-10123456 y 4 3 2 1 -2 -3 -4 Object Enlarge the shape by a scale factor of -1 about the point (0,2) Image Negative Enlargement Bro Tip: When the scale factor is negative, the principle is exactly the same. Any ‘negative distances’ go in the opposite direction.

13. x-5-4-3-2-10123456 y 4 3 2 1 -2 -3 -4 Enlarge the shape by a scale factor of -2 about the point (1,1) Object Image Test Your Understanding

14. x-5-4-3-2-10123456 y 4 3 2 1 -2 -3 -4 Object Enlarge the shape by a scale factor of -0.5 about the point (0,2) Image Test Your Understanding

15. x-5-4-3-2-10123456 y 4 3 2 1 -2 -3 -4 Enlarge the shape by a scale factor of -1.5 about the point (1,1) Object Image Test Your Understanding

16. Worksheet Time

17. Answers

19. Enlargement of scale factor 2 about the origin. ?

20. Answers B

22. Enlargement by a scale factor of 3 about the origin. ?

23. Answers Enlargement of scale factor 3 about the origin. ?

24. x-5-4-3-2-10123456 y 4 3 2 1 -2 -3 -4 Object Image Recap ?? ?

25. x-5-4-3-2-10123456 y 4 3 2 1 -2 -3 -4 Object Image Recap ?? ?

26. Year 9 Combined Transformations Dr J Frost (jfrost@tiffin.kingston.sch.uk) Last modified: 5 th October 2013

27. x-5-4-3-2-10123456 y 4 3 2 1 -2 -3 -4 Object Image after rotation Final Image (Draw this in your book!) Rotate this object 90 clockwise about the origin, then reflect in the line y = x. How could we have done the same with just one transformation? Starter

28. x-5-4-3-2-10123456 y 4 3 2 1 -2 -3 -4 Object Final Image On the same axes, now reflect the object in the y axis followed by the x axis. Again, how could we have done the same with just one transformation?

29. x-5-4-3-2-10123456 y 4 3 2 1 -2 -3 -4 Object Image Sketch the following in your books. List the sequence of two transformations which results in the image.

30. x-5-4-3-2-10123456 y 4 3 2 1 -2 -3 -4 Object Work in pairs: Both sketch the following in your book. Pick a reflection and a rotation of your choice*, sketch the image, then get your neighbour to try and work out the transformations you choose from the image. *Although to keep things simple, the line of reflection must be in the form x = c, y = c, y = x or y = -x