Similarity in mathematics has a precise meaning, unlike its usage in everyday life. 2 shapes are said to be similar if they fulfill the following **2 conditions**:

- The corresponding angles on the 2 shapes are equal
- One shape is an enlargement of the other shape by a scale factor

Let’s start with a simple example to demonstrate these 2 conditions.

BUT…

With similar shapes you can be asked 2 type of questions.

- Find the scale factor given two similar shapes
- Find a missing side given two similar shapes

Finding the Scale Factor

To find the scale factor of two similar shapes, do the following:

- Take two
**corresponding sides** and divide the larger one by the smaller one.

Finding a missing side

To find a missing side, we need to know the scale factor a shape has been increased (or decreased) by. Here is how it is done.

Similarity in mathematics has a precise meaning, unlike its usage in everyday life. 2 shapes are said to be similar if they fulfill the following

2 conditions:Let’s start with a simple example to demonstrate these 2 conditions.

BUT…

With similar shapes you can be asked 2 type of questions.

Finding the Scale Factor

To find the scale factor of two similar shapes, do the following:

corresponding sidesand divide the larger one by the smaller one.Finding a missing side

To find a missing side, we need to know the scale factor a shape has been increased (or decreased) by. Here is how it is done.

## Nouri Dib