Final answer:
To find an angle equal to 100 degrees when two parallel lines are cut by a transversal, we should identify alternate interior angles, corresponding angles, or vertical angles relative to the given angle, as they would also measure 100 degrees. Without the positions of the numbered angles, a definitive answer is not possible.
Step-by-step explanation:
The question involves understanding the relationships between angles formed when a pair of parallel lines is cut by a transversal line. Given that lines m and n are parallel and cut by transversal l, and one of the angles measures 100 degrees, we can determine the measure of other angles using the concepts of alternate interior angles, corresponding angles, and vertical angles.
Here, without a diagram, it is important to visualize or recall that angles formed in the configuration of two parallel lines cut by a transversal can be equal or supplementary (adding up to 180 degrees), depending on their relative positions. Specifically, for any angle measuring 100 degrees, the corresponding angle, alternate exterior angle, and the vertical angle would also measure 100 degrees.
Without knowing the exact positions of angles 2, 3, 4, and 5, we cannot determine which is equal to 100 degrees. However, if the angle measuring 100 degrees is an interior angle on one side of the transversal, then the alternate interior angle on the other side of the transversal would be equal to it, which would be one of the numbers listed (2, 3, 4, or 5).