Answer:
B. complementary angles
Step-by-step explanation:
the angles form a right angle, or a 90 degree angle.
angles that form a 90 degree angle or right angle are known as complementary angles
reasons its not other answer choices:
supplementary angles : form 180 degree angles. angles a and b form 90 degree angles not 180 degree angles therefore angles a and b are not supplementary angles
vertical angles: vertical angles are congruent and are vertically aligned with each other. angles a and b are not vertically aligned with each other therefore they cannot be vertical angles.
