1. Congruence, Similarity and Enlargement Understand congruence and similarity Understand the effect of enlargement for perimeter, area and volume of shapes and solids

2. Similar Two shapes are SIMILAR if the only difference is size (and possibly the need to turn or flip one around) http://www.mathsisfun.com/geometry/similar.html

3. Congruent Congruent shapes are the same shape and size. Same size, area, angles and line lengths. http://www.mathsisfun.com/geometry/congruent.html

4. Which of the following shapes is similar to the one shown? 1 a:b:c:d:

6. Which of the following shapes is similar to the one shown? 2 c:b:a:d:

8. b: 18 cmd: 12 cma: 20 cmc: 16 cm The photograph has width 3 cm and length 4 cm. An enlargement has a width of 15 cm. What will be the new length? 3

9. 3cm 4cm 15cm New length? x ?

10. b: 4.5 cmd: 7.5 cma: 4 cmc: 5.5 cm The photo has width 3 cm and length 5 cm. An enlargement has length 7.5 cm. What will be the new width? 4

11. 4 3cm New Width? x ? 5cm 7.5cm x ?

12. Which of these shapes is congruent to the one shown on the right? 5 d:a:b:c:

14. b: No d: Not possible to say a: Yesc: Sometimes Are all rectangles similar? 6

16. b: No d: Not possible to say a: Yesc: Sometimes Are all triangles similar? 7

18. b: 14 cm 2 d: 48 cm 2 a: 6 cm 2 c: 24 cm 2 The area of a photograph is 12 cm 2. If the shape is enlarged by a scale factor of 2, what will be the new area? 8

19. 8 Look what happens to the area when we double the sides. How many times bigger is it?

20. b: 64 cm 3 d: 16 cm 3 a: 128 cm 3 c: 32 cm 3 An OXO cube measures 2cm by 2 cm by 2 cm, giving a volume of 8 cm 3. If it were enlarged by scale factor 2, what would be the new volume? 9

21. 9 If we double the length of every side of the cube, how many cubes are there now? And each cube has a volume of ---? So what is the new volume?

22. b: 740 ydsd: 3330 ydsa: 373 ydsc: 1110 yds The perimeter of the field at Stamford Bridge is 370 yards. If the field were enlarged by scale factor three, what would be the new perimeter? 10

23. The perimeter of the field at Stamford Bridge is 370 yards. If the field were enlarged by scale factor three, what would be the new perimeter? 10 Perimeter is a length. What happens when you multiply a length by a scale factor?

24. Answers

25. b:d:a:c: Which of the following shapes is similar to the one shown? 1

26. b:d:a:c: Which of the following shapes is similar to the one shown? 2

27. b: 18 cmd: 12 cma: 20 cmc: 16 cm The photograph has width 3 cm and length 4 cm. An enlargement has a width of 15 cm. What will be the new length? 3

28. b: 4.5 cmd: 7.5 cma: 4 cmc: 5.5 cm The photo has width 3 cm and length 5 cm. An enlargement has length 7.5 cm. What will be the new width? 4

29. b:d:a:c: Which of these shapes is congruent to the one shown on the right? 5

30. b: No d: Not possible to say a: Yesc: Sometimes Are all rectangles similar? 6

31. b: No d: Not possible to say a: Yesc: Sometimes Are all triangles similar? 7

32. b: 14 cm 2 d: 48 cm 2 a: 6 cm 2 c: 24 cm 2 The area of a photograph is 12 cm 2. If the shape is enlarged by a scale factor of 2, what will be the new area? 8

33. b: 64 cm 3 d: 16 cm 3 a: 128 cm 3 c: 32 cm 3 An OXO cube measures 2cm by 2 cm by 2 cm, giving a volume of 8 cm 3. If it were enlarged by scale factor 2, what would be the new volume? 9

34. b: 740 ydsd: 3330 ydsa: 373 ydsc: 1110 yds The perimeter of the field at Stamford Bridge is 370 yards. If the field were enlarged by scale factor three, what would be the new perimeter? 10