Question

Question 1 (0.5 points)

Given a = 31, A = 84 degrees, and b = 20, use the Law of Sines to solve for B. Round
your answer to the nearest degree, and enter the number only. Note: The figure is
not drawn to scale.

Answer 1

39.91 degrees.

Explanation:

Formula

Sin(A)/a = Sin(B) / b

Givens

• A = 84
• a = 31
• B = ?
• b = 20

Solution

Sin(84)/31 = Sin(B)/20

20*Sin(84) / 31 = Sin(B)

Sin(B) = 0.6416

B = 39.91 degrees.

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This looks like it is right, but you should check. Let h be the height opposite angle A.

h/20 = sin(39.91)

h = 20*sin(39.91)

h = 12.83

31 has to be longer than that amount (which it is.) So there is one solution.