The Triangle Angle Sum Theorem states that the sum of the angles in a triangle is always 180 degrees.
Let the three angles of the triangle be \( A \), \( B \), and \( C \). Given that:
- \( A = 40^\circ \)
- \( B = 65^\circ \)
We can find the third angle \( C \) using the theorem:
\[ C = 180^\circ - (A + B) \]
Now, substituting the known values:
\[ C = 180^\circ - (40^\circ + 65^\circ) \] \[ C = 180^\circ - 105^\circ \] \[ C = 75^\circ \]
Therefore, the measure of the third angle is \( 75^\circ \).