When the index and horizon mirrors of a properly adjusted sextant are at an angle of 45° to each other, the arc reads __________.

Question

When the index and horizon mirrors of a properly adjusted sextant are at an angle of 45&deg; to each other, the arc reads __________.

Accepted Answer

Option D: 90&deg;. Marine sextants utilize a double-reflection principle where the angle between mirrors is half the measured angle on the arc. When the index and horizon mirrors are set at 45°, the resulting arc reading is exactly double, equaling 90°.

When the index and horizon mirrors of a properly adjusted sextant are at an angle of 45&deg; to each other, the arc reads __________.

When the index and horizon mirrors of a properly adjusted sextant are at an angle of 45° to each other, the arc reads __________.