1. MM3 – Similarity of two-dimensional Figures, Right-Angled Triangles
Vocabulary (as per MM1 and MM2):
accuracy
adjacent
angle of depression
angle of elevation
area
capacity
composite figure
cosine ratio
cylinder
error
field diagram
hypotenuse
opposite
perimeter
quadrant
rate
ratio
right prism
scale diagram
scale factor
scientific notation
significant figures
similar
sine ratio
standard prefix
tangent ratio
trigonometry
unitary method
volume

2. Basic Concepts: Calculate measurements from scale diagrams
Calculate and use scale factors for similar figures
Calculate sine, cosine and tangent ratios and use them to find side lengths and angles in triangles
Calculate angles of depression and elevation
Solve practical problems using scale factor and trigonometry

3. Similar Figures
Two figures are similar if one is an enlargement of the other. An enlargement factor is the same as the scale factor.

14. Scale Drawings
A scale drawing is a representation of the original, with all angles the same and all sides in proportion to the original.

15. NOTE: The majority of activities in this section depend on measurement – see textbook for more questions.

19. Right-Angled Trigonometry
You SHOULD remember working with Pythagoras’ Theorem and trigonometry from junior school…

20. Pythagoras

23. The three trigonometric ratios:
These three ratios can be used to find sides or angle in triangles: A good visual cue for this is: 𝑺 𝑶 𝑯 𝑪 𝑨 𝑯 𝑻 𝑶 𝑨

25. Using your calculator

28. More Calculator Work…

29. Finding angles using trigonometry

32. Finding sides in triangles using trigonometry:

35. Unknown in the Denominator

37. Angles of Elevation and Depression
The angle of elevation Is when you look UP at an object. The angle of depression is when you look DOWN at an object. Both are measured from the horizontal.

41. Applications to problems