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Find the measure of angle B using the law of sines

Find the measure of angle B using the law of sines-example-1

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Answer: angle B = 15.04104216 degrees approximately

Round that however you need to.

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Step-by-step explanation:

The lowercase letters a,b,c are used as side lengths while the uppercase letters A,B,C are the angles.

  • Side 'a' is opposite angle A
  • Side b is opposite angle B
  • Side c is opposite angle c

From the diagram, we have the following info:

  • side b = 22
  • side c = 63
  • side C = 48

Use the law of sines to find B

sin(B)/b = sin(C)/c

sin(B)/22 = sin(48)/63

sin(B) = 22*sin(48)/63

sin(B) = 0.25951089143656

B = arcsin(0.25951089143656)

B = 15.04104216 which is approximate

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Another possible value of B is

B = 180-arcsin(0.25951089143656) = 164.95896

Since

sin(15.04104216) = sin(164.95896) = 0.2595109

However, notice that this leads to

A+B+C = 180

A+ 164.95896 + 48 = 180

A + 212.95896 = 180

A = 180 - 212.95896

A = -32.95896

But we cannot have a negative angle. Therefore only one triangle is possible here.

The only solution is approximately B = 15.04104216

User Levi Ramsey
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