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I need help figuring out how to find sides a and b using the law of sine

I need help figuring out how to find sides a and b using the law of sine-example-1
User Instance
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1 Answer

16 votes
16 votes

Given the triangle ABC below.

a is the side facing b is the side facing

c is the side facing

We ara interested in calculating the value of side a and b.

To do this, we need to apply the "sine rule"

Sine rule state that


(a)/(\sin A)=(b)/(\sin B)=(c)/(\sin C)

Where

a is the side facing b is the side facing

c is the side facing

To calculate b,

B = 95 , b = ?

C = 48, c=100


\begin{gathered} (b)/(\sin B)=(c)/(\sin C) \\ (b)/(\sin 95)=\frac{100}{\sin \text{ 48}} \\ \\ b\text{ x sin48=100 x sin95} \\ b=\frac{100\text{ x sin95}}{\sin 48} \\ b=134.05 \end{gathered}

b = 134 ( to nearest whole number)

To calculate a:

A = 37, a = ?

C = 48, c=100


\begin{gathered} (a)/(\sin A)=(c)/(\sin C) \\ (a)/(\sin37)=(100)/(\sin 48) \\ a\text{ x sin48 = 100 x sin37} \\ a=\frac{100\text{ x sin37}}{\sin 48} \\ a=80.98 \\ \end{gathered}

a = 81 ( to the nearest whole number)

I need help figuring out how to find sides a and b using the law of sine-example-1
User Shanda
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2.9k points