Question

Which of these shapes below is an enlargement of shape x by a scale factor of 2

Answer 1

What is a scale factor?

A scale factor consists of two or more shapes who look the same but have different scales or measures. A scale factor of 2 means that the new triangle is two times the size of the original.

If we look at shape x, we can see it has a base of 4, and a height of 3. If we also know that a scale factor of two means that the new shape will be twice as large, we can use an equation that looks like this:

(Base/height × scale factor = new base length)

• 4 × 2 = 8 (b)

• 3 × 2 = 6 (h)

Now that we have these numbers, we can take them and see which shape matches the new length.

1. Shape A has a base of 6, and a height of 5.
2. Shape B has a base of 6, and a height of 8.
3. Shape C has a base of 8, and a height of 8.
4. Shape D has a base of 8, and a height of 6.
5. Shape E has a base of 6, and a height of 6.
6. Shape F has a base of 8, and a height of 6.

Shape D has a base of 8 and a height of 6, meaning that it has a scale factor 2 compared to shape x.

Therefore Shape D is the answer.