When two lines intersect, they will have a point of intersection where angles around this point will add up to 360°
Since the lines can intersect in many different ways, we cannot assume that the angles form will all be right angles (although this is possible, it doesn't always happen). The four angles can't also be all of the same sizes.
Refer to the diagram below, the intersection will definitely two pairs of vertical angles, x and y.
Answer: When a pair of lines intersect, the vertical angles are congruent.
