The correct answer is quadrant.
Quadrant is a method used to determine latitude. Chronometer is used to measure time. Astrolabe is used by navigators and astrologers. Cross-staff or Jacob's staff is used to measure angles. So the correct answer would be quadrant. I hope this helped you.
Answer:
18.9
Step-by-step explanation:
30 divided by 3. Their are 3 sets of ten by 30 positives