Checking understanding of similarity | Starter Quiz | Oak National Academy

Two shapes are (a)   if the only difference between them is their size. Their side lengths are in the same proportions.

Answer explanation

Two shapes are similar if the only difference between them is their size. Their side lengths are in the same proportions. Similar shapes are enlargements of each other.

The __________ is the multiplier between similar shapes that describes how large one shape is compared to the other.

• centre of enlargement

• line of reflection

• scale factor

• vector

Answer explanation

The scale factor is the multiplier between similar shapes that describes how large one shape is compared to the other.

Which rectangle is a correct enlargement of of rectangle R?

• A

• B

• C

Answer explanation

Rectangle B is an enlargement of rectangle R by a scale factor of 2.

Triangle A has been enlarged by a scale factor of 2 to get triangle B. Match each unknown length from triangle B with its size.

• 10 cm

• 8 cm

• 6 cm

Each angle in an equilateral triangle is 60°. If an equilateral triangle is enlarged by a scale factor of 2, each of its angles will be (a)   °.

Answer explanation

If an equilateral triangle is enlarged by a scale factor of 2, each of its angles will still be 60°.