Solve Mixed Angle Problems

In this activity, we will calculate missing angles using different angle rules.

Let's recap the rules first!

Recap - Make a note of these!

Angles at a point = 360^o

Angles on a straight line = 180^o

Angles in a triangle = 180^o

Angles on parallel lines - Z shape-  angles are equal -  alternate angles

Angles on parallel lines - F shape-  angles are equal -  corresponding angles

Angles on parallel lines - C shape-  angles add up to 180^o -  co-interior angles

One more!

Vertically opposite angles:

This is when two lines form a cross X

The opposite angles are equal

You can see from the diagram that if A was 60^o the opposite A would be 60^o too.

Likewise, if B is 120^o the other B is too.

Also, A and B form a straight line. (you can see below)

So, if A = 60^o

B = 180 - 60 =120^o

Have you made some notes? 

You can look back at these rules at any point by clicking on the red help button on the screen.

Are you ready to test yourself on all your angle rules?!!