Answer
Yes, the transversal line must be perpendicular to another parallel line.
Work Step by Step
Let the angle between the first parallel line and the transversal be \[\measuredangle 1\] and the angle between the second parallel line be \[\measuredangle 2\]
It is known that the transversal intersects the first parallel line at 90°. Then, the value of \[\measuredangle 1\] will be 90°
Now, \[\measuredangle 2\]and \[\measuredangle 1\] are corresponding angles and the measurement of corresponding angles are equal.
Then, compute the value of angle 2 as follows:
\[\begin{align}
& \measuredangle 2=\measuredangle 1 \\
& \measuredangle 2=90{}^\circ
\end{align}\]
Thus, \[\measuredangle 2\]is having the measurement of 90°
Hence, the transversal intersects both parallel lines at 90°
