Complementary angles are two angles that sum to 90 degrees. Given that \( m\angle 5 = 39^\circ \), you can write the equation for the complementary angle \( m\angle 6 \) as follows:
\[ m\angle 6 + 39^\circ = 90^\circ \]
So the correct response would be:
m∠6 + 39° = 90°