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Find the sides and angles of the triangle.

Find the sides and angles of the triangle.-example-1
User Gang YIN
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1 Answer

4 votes

Answer:

a ≈ 6.8, B ≈ 50°, C ≈ 82°

Explanation:

You want to solve the triangle with A=48°, b=7, c=9.

Law of Cosines

The relation given by the law of cosines is ...

a² = b² +c² -2bc·cos(A)

a² = 7² +9² -2·7·9·cos(48°) ≈ 45.6895

a ≈ √45.6895 ≈ 6.76 ≈ 6.8

Law of Sines

The law of sines can be used to find one of the other angles:

sin(C)/c = sin(A)/a

C = arcsin(c/a·sin(A)) ≈ arcsin(9/6.7594·sin(48°)) ≈ 81.68° ≈ 82°

The remaining angle can be found from the sum of angles in a triangle:

B = 180° -A -C = 50°

The solution is a ≈ 6.8, B ≈ 50°, C ≈ 82°.

Find the sides and angles of the triangle.-example-1
User Horsh
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9.0k points