Use the triangle angle sum theorem to find the measure of the third angle if the first and second angle measure 63 and 40.
The triangle angle sum theorem states that the sum of the measures of the angles in any triangle is always 180 degrees.
Let's label the third angle as x.
Therefore, the equation would be:
63 + 40 + x = 180.
Combine like terms:
103 + x = 180.
Subtract 103 from both sides:
x = 180 - 103.
x = 77.
Therefore, the measure of the third angle is 77 degrees.