Answer:
B = 43°
a = 11.0
b = 10.2
Explanation:
The relationship between side lengths and trig functions in a right triangle is summarized in the mnemonic SOH CAH TOA. It tells you, for example, ...
Sin = Opposite/Hypotenuse
Cos = Adjacent/Hypotenuse
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Applied to this triangle, the unknown sides can be found from ...
sin(47°) = a/15
a = 15·sin(47°) ≈ 11.0
and
cos(47°) = b/15
b = 15·cos(47°) ≈ 10.2
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The second acute angle in a right triangle is the complement of the first:
B = 90° -47° = 43°