Answer:
13.2 m
Explanation:
The Law of Sines can be used to solve a triangle when angles and one side are known.
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setup
The angles of a triangle total 180°, so the missing angle A is ...
∠A = 180° -48° -54° = 78°
The Law of Sines tells us ...
a/sin(A) = b/sin(B)
a/sin(78°) = (10.0 m)/sin(48°)
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solution
Multiplying by sin(78°), we find ...
a = sin(78°)/sin(48°)×(10.0 m) ≈ 0.978148/0.743145×(10.0 m)
a = 13.1623 m
The length of side 'a' is approximately 13.2 meters.