Final answer:
In a right triangle representing the scenario of keys falling from a tower, the known side is the vertical distance, and the unknown side is the horizontal distance to the base. Trigonometry is used to relate the known side as the opposite and the unknown side as the adjacent.
Explanation:
Known side: In a right triangle formed by the keys falling from a tower, the vertical distance from the top of the tower to the ground is the known side.
Unknown side: The horizontal distance from the base of the tower to where the keys landed is the unknown side.
Using trigonometry, the known side is the opposite side while the unknown side is the adjacent side.
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