Definition of an exterior angle
At each vertex of a triangle, an exterior angle of the triangle may be formed by extending ONE SIDE of the triangle. See picture below.
Calculating the Angles
We can use equations to represent the measures of the angles described above. One equation might tell us the sum of the angles of the triangle. For example,
x + y + z = 180
If you change both to a fraction you would see that you have 1/6 and 1/4 (.25 as a fraction). So 1/5 would be in between them.
You could also change both as a decimal. 1/6 =.166666 and .25 so any number in between them would be correct such as .2 which is the same as 1/5.
Note on how to solve such equation:
This is a quadradic equation. The figure shown is a parabola. This parabola opens downward. Now, this information is not necessary important for this particular situation; however, it needs to be retained for said class or for the near future.
The equation for a quadradic function is: f(x)=x^2+2
when x=-2, y=1