In this activity, we will be learning to calculate missing angles. 

The angles around a point add to 360°

We might also call this 'angles in a full turn' or 'rotation'.

We can find missing angles using addition and subtraction. 

Let's try an example now. 

Example

Find the size of the missing angle in this diagram. 

Answer

We can calculate the missing angle by subtracting the known angles from 360°

360° - 25° - 105° - 90º = 140

So, the missing angle is 140°

Now it's time for you to try some more questions like this one.  

Good luck!