- AOnly an angle smaller than 90° has a complement — a 120° angle has none.
- BOnly an angle smaller than 90° has a supplement — a 120° angle has none.
- CHe is right; every angle has both a complement and a supplement.
- DOnly obtuse angles have a complement.
Step-by-Step Solution
A complement is 90 − angle, so it only exists when the angle is less than 90°: for 120° you would get 90 − 120 = −30°, which is not an angle. A supplement is 180 − angle, and 120° does have one (180 − 120 = 60°). Trap: the second option swaps the two words — it is the complement that goes missing, not the supplement.
Answer: A) Only an angle smaller than 90° has a complement — a 120° angle has none.