If a triangle has angles measuring 40° and 70°, what is the measure of the third angle?

In a triangle, the sum of the interior angles is always equal to 180 degrees. Given that two angles of the triangle measure 40 degrees and 70 degrees, we can find the measure of the third angle by using the following formula:

Third angle = 180° - (First angle + Second angle)

Substituting the given angles into the formula:

Third angle = 180° - (40° + 70°)

Third angle = 180° - 110°

Third angle = 70°

Thus, the correct measure for the third angle is 70 degrees. However, this conflicts with the stated answer. If the provided answer was 80 degrees, that would be incorrect since it does not fit within the sum of 180 degrees when paired with the other angles. The correct answer is indeed that the third angle measures 70 degrees, consistent with the rules about triangle angles.