To find \( m\angle A \) given that \( m\angle C = 75^\circ \), we can use the property that adjacent angles formed by intersecting lines are supplementary. This means that the sum of the measures of adjacent angles is \( 180^\circ \).
Since angle \( C \) is adjacent to angle \( A \), we can write:
\[ m\angle A + m\angle C = 180^\circ \]
Substituting \( m\angle C = 75^\circ \) into the equation:
\[ m\angle A + 75^\circ = 180^\circ \]
Now, solve for \( m\angle A \):
\[ m\angle A = 180^\circ - 75^\circ \] \[ m\angle A = 105^\circ \]
Thus, \( m\angle A = 105^\circ \). The correct answer is:
105°
1 answer