Answers:
- One possible equation to solve is tan(x) = 4/15
- That solves to roughly 15 degrees
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Explanation:
Refer to the diagram below.
The segment AB is the player's height of 6 ft.
The segment CD is the hoop's height, which is 10 ft.
There is a point E on CD such that rectangle BACE forms. This will help us form ED later.
Angle EBD is what we're after, which I'll call x.
Since the free throw line is 15 ft from the basket, this means segments EB and AC are 15 ft each.
In rectangle BACE, the side EC is opposite AB. So both of those sides are 6 ft each.
Since CD = 10 and EC = 6, this must mean ED = CD-EC = 10-6 = 4.
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To summarize, we found that ED = 4 and EB = 15.
We'll focus our attention entirely on triangle EBD
We have two known legs of the triangle, specifically the opposite and adjacent sides.
So we'll use the tangent ratio.
tan(angle) = opposite/adjacent
tan(B) = ED/EB
tan(x) = 4/15 .... is the equation to solve
x = arctan(4/15) .... same as inverse tangent or
x = 14.931417 ..... make sure to be in degree mode
x = 15 ..... rounding to the nearest whole degree
So that unknown angle in the diagram is approximately 15 degrees
