Similarity And Congruence

Question 1

When are two shapes similar?

Answer 1

Two shapes are similar if:

• The angles are the same
• The ratios of the sides are the same

Question 2

If a shape is enlarged by linear scale factor k, what is the area of the shape enlarged by?

Answer 2

Are scale factor k²

Question 3

When a shape is enlarged by linear scale factor k, what is the volume of the shape enlarged by?

Answer 3

Volume scale factor k³

Question 4

When going from a ‘big’ to a ‘little’ shape, how do you calculate the length of the side you are trying to find?

Answer 4

The little given side/it’s equivalent given ‘big’ side

(Fraction will always be bottom heavy)

x

the long length that is equivalent to the small length trying to be found.

Question 5

When going from a ‘little’ to a ‘big’ shape, how do you calculate the length of the side you are trying to find?

Answer 5

The big given side/it’s equivalent given little side

(Fraction will always be top heavy (over one))

x

the short length that is equivalent to the long length trying to be found.