Using the scale factor for enlarging an area
I can calculate the scale factor used to enlarge an area and use it to find missing lengths.
Using the scale factor for enlarging an area
I can calculate the scale factor used to enlarge an area and use it to find missing lengths.
Lesson details
Key learning points
- You can calculate the scale factor from the two areas.
- Having calculated the scale factor, you can find missing lengths.
Common misconception
A linear scale factor can only be found by finding the multiplicative relationship between two corresponding lengths.
A linear scale factor can also be found by square rooting an area scale factor, where an area scale factor is found from the multiplicative relationship between the area of two similar 2D shapes, or corresponding faces on two similar 3D shapes.
Keywords
Similar - Two shapes are similar if the only difference between them is their size. Their side lengths are in the same proportions.
Invariant - A property of a shape is invariant if that property has not changed after the shape is transformed.
Enlargement - Enlargement is a transformation that causes a change of size.
Scale factor - A scale factor is the multiplier between similar shapes that describes how large one shape is compared to the other.
Licence
This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
Video
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Starter quiz
6 Questions
Linear scale factor: $$5$$ -
Area scale factor: $$25$$
Linear scale factor: $$\frac{1}{2}$$ -
Area scale factor: $$\frac{1}{4}$$
Linear scale factor: $$3$$ -
Area scale factor: $$9$$
Linear scale factor: $$0.1$$ -
Area scale factor: $$0.01$$
Linear scale factor: $$10$$ -
Area scale factor: $$100$$
Linear scale factor: $$\frac{3}{2}$$ -
Area scale factor: $$\frac{9}{4}$$
Exit quiz
6 Questions
