Similar shapesL.O.Calculate unknown sides in similar triangles

Two shapes are said to be similar if one can be obtained from the other by uniformly scaling, possibly with additional translation, rotation or reflection.

Are these triangles similar?

3 cm

4 cm

5 cm

6 cm10 cm

8 cm

A B

If the shapes are similar what can you tell about the angles in the shapes?

IDENTIFY SIMILAR SHAPES

Are the shapes similar?

2 cm

2 cm

6 cm

If the shapes are similar what can you tell about the angles in the shapes?

6 cmBA

IDENTIFY SIMILAR SHAPES

Are the shapes similar?6 cm

10 cm

2 cm

4 cmB

A

If the shapes are similar what can you tell about the angles in the shapes?

IDENTIFY SIMILAR SHAPES

Are the shapes similar?

5 cm

10 cm2 cm

4 cm

BA

If the shapes are similar what can you tell about the angles in the shapes?

IDENTIFY SIMILAR SHAPES

Are these triangles similar?

3 cm

4 cm

5 cm

12 cm

15 cm9 cm

A

B

IDENTIFY SIMILAR SHAPES

If the shapes are similar what can you tell about the angles in the shapes?

Calculating unknown sides

3 cm

15 cm

7 cmX cm

Calculating unknown sides

X cm

Y cm

Calculating unknown sides

5 cm 8 cm

Y cm

9 cm X cm

34.2 cm

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Which pair are similar?

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Question!

Plenary

Write a key word from today’s lesson on your whiteboard

Plenary

5 cm 8 cm

Y cm

15 cm X cm

36 cm

Find X and Y Show your method clearly