5
QuizMultiple Choice

Applying Trigonometric Identities and Equations — Test

Question 5 • Precalculus

What are the possible remaining angle measures in triangle ABC with m angle cap A is equal to 40 degrees , AC is equal to 60 , and BC is equal to 45 ?

Answer
A
m angle cap b almost equal to 59 degrees , m angle cap c almost equal to 81 degrees
B
m angle cap b almost equal to 121 degrees , m angle cap c almost equal to 19 degrees and m angle cap b almost equal to 59 degrees , m angle cap c almost equal to 81 degrees
C
No triangle can be formed with these measures.
D
m angle cap b almost equal to 121 degrees , m angle cap c almost equal to 19 degrees

Explanation

By the sine rule, sin B / 60 = sin 40° / 45, so sin B ≈ 0.857. This gives two possible angles: B ≈ 59° or B ≈ 121°, since angles with the same sine can be supplementary. Using A + B + C = 180°, the corresponding values of C are about 81° and 19°. Therefore, both pairs listed in choice B are possible.

AI-written and checked against the verified answer.

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