Question

Which pair of angles must be supplementary?

2 lines intersect to form right angles. Another line goes through the lines diagonally to form 6 angles. From top left, clockwise, the angles are 2 (90 degrees), 1, 6, 5 (90 degrees), 4, 3.
Angle 1 and Angle 6
Angle 2 and Angle 5
Angle 5 and Angle 4
Angle 6 and Angle 2

Answer 1

Angle 2 and Angle 5.

Reason: Both are right angles (90° each), so their measures add to 180° — they are supplementary.