1. 1 Exterior Angles of a Triangle Stage 5 - Year 9 Press Ctrl-A ©2009 – Not to be sold/Free to use

2. 2 Proof Exterior Angle Interior Opposite The Exterior Angle is the Sum of the Interior Opposite Angles Interior Opposite Exterior Angle Angle Exterior Angle of a Triangle.

3. 3 Exterior Angle Interior Opposite The Exterior Angle is the Sum of the Interior Opposite Angles Interior Opposite A + B = CA + B = CA + B = CA + B = C A B C Exterior Angle Angle Exterior Angle of a Triangle.

4. 4 Interior Opposite Example 1 45 o 70 o C 70 o + 45 o = C 115 o = C C = 115 o Exterior Angle Angle Exterior Angle of a Triangle.

5. 5 Exterior Angle Angle Interior Opposite Example 2 AoAoAoAo 70 o 120 o A + 70 o = 120 o -70 -70 A = 50 o Exterior Angle of a Triangle.