A sextant is a navigational instrument used to measure the angle between a celestial object (like the sun, moon, or a star) and the horizon, which is crucial for determining a ship's position at sea. It works by using mirrors and telescopes to reflect the image of the celestial body down to the horizon line, allowing the navigator to measure the angle between them. This angle, along with the time of measurement, is then used to calculate the ship's latitude and longitude. , which is crucial for determining a ship's position at sea. It works by using mirrors and telescopes to reflect the image of the celestial body down to the horizon line, allowing the navigator to measure the angle between them. This angle, along with the time of measurement, is then usedA sextant is a navigational instrument used to measure the angle between a celestial object (like the sun, moon, or a star) and the horizon, which is crucial for determining a ship's position at sea. It works by using mirrors and telescopes to reflect the image of the celestial body down to the horizon line, allowing the navigator to measure the angle between them. This angle, along with the time of measurement, is then used to calculate the ship's latitude and longitude. to calculate the ship's latitude and longitude.