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# Finding Missing Angles

The three examples below show how angle relationships and the properties of triangles can be used to find unknown angles. You can review angle properties here.

## Reminders

• Sum of the angles in a triangle = 180°
• Sum of the angles in a quadrilateral = 360°
• Opposite angles are equal
• For two parallel lines and a transversal,
• corresponding angles are equal, and
• alternate angles are equal.

Work through the examples below with your children. Discuss alternate ways of finding the missing angles as there are often other ways of finding them.

## Finding Angles: Example 3

In the above examples the discovery of each angle followed on from finding other angles. The missing angles will not always be labeled a, b, c, d, etc. so the sequence in which to find angles might not be obvious. Sometimes it is best to just start finding whatever angles you can and keep going until all the ones that are required are found.