[1] First, remember that the sum of the angles in a triangle must add up to 180*.
[2] We are told two of the angles, 44* and 66*, but we are missing the third.
[3] Combining [1] and [2], we know that 44* + 66* + ? = 180*. In other words,
110* + ? = 180*
so,
? = 70*
The missing angle 3 is equal to 70 degrees.
