Which is an example of a conditional statement?

(2 points)
1 If two angles add up to 90 degrees, then they are complementary angles.
2 The angles of triangles add up to 180 degrees.
3 The angles of triangles add up to 180 degrees.
4 Vertical angles are always congruent.

1 If two angles add up to 90 degrees, then they are complementary angles.