One of the angles formed at the intersection of two straight lines is equal to 25 degrees.

One of the angles formed at the intersection of two straight lines is equal to 25 degrees. Find the values for the remaining angles.

Note that when two straight lines intersect (in Euclidean geometry studied at school, two straight lines can intersect only at one point) 4 angles are formed. These angles are vertical in pairs. That is, each corner with one of the remaining ones is vertical. Vertical angles have the same degree measure, so one of the angles in our case is equal to this one. The two remaining corners are adjacent to the given one. Two adjacent angles add up to a flat angle, so the degree measure of the two remaining angles is:
180 – 25 = 155 degrees.