Get the most out of your questions with the extensive resources available on IDNLearn.com. Join our community to receive prompt and reliable responses to your questions from experienced professionals.

Law of Sines:

[tex]\[ \frac{a}{\sin A} = \frac{b}{\sin B} \][/tex]


Sagot :

Certainly! Let's use the Law of Sines to solve this problem where we are given:

- Side [tex]\( a = 4 \)[/tex]
- Angle [tex]\( A = 30^\circ \)[/tex]
- Side [tex]\( b = 5 \)[/tex]

We need to find [tex]\( B \)[/tex], an angle opposite side [tex]\( b \)[/tex].

### Step-by-Step Solution:

1. Convert Degrees to Radians:
First, convert angle [tex]\( A \)[/tex] from degrees to radians. The conversion factor is [tex]\( \pi \)[/tex] radians for [tex]\( 180^\circ \)[/tex]:
[tex]\[ A = 30^\circ \times \frac{\pi}{180^\circ} = \frac{\pi}{6} \text{ radians} \][/tex]

2. Apply the Law of Sines:
According to the Law of Sines:
[tex]\[ \frac{a}{\sin A} = \frac{b}{\sin B} \][/tex]
Substitute the known values:
[tex]\[ \frac{4}{\sin(30^\circ)} = \frac{5}{\sin B} \][/tex]

3. Calculate [tex]\(\sin(30^\circ)\)[/tex]:
We know from trigonometry that:
[tex]\[ \sin(30^\circ) = \frac{1}{2} \][/tex]
Therefore:
[tex]\[ \frac{4}{\frac{1}{2}} = \frac{5}{\sin B} \][/tex]

4. Solve for [tex]\(\sin B\)[/tex]:
This simplifies to:
[tex]\[ 4 \times 2 = \frac{5}{\sin B} \][/tex]
[tex]\[ 8 = \frac{5}{\sin B} \][/tex]
Rearrange to isolate [tex]\(\sin B\)[/tex]:
[tex]\[ \sin B = \frac{5}{8} = 0.625 \][/tex]

5. Find Angle [tex]\( B \)[/tex]:
The value of [tex]\(\sin B\)[/tex] gives us:
[tex]\[ B = \arcsin(0.625) \][/tex]
Calculating [tex]\(\arcsin(0.625)\)[/tex] yields:
[tex]\[ B \approx 0.675 \text{ radians} \][/tex]

6. Convert Radians to Degrees:
Finally, convert angle [tex]\( B \)[/tex] from radians to degrees. The conversion factor is [tex]\( 180^\circ / \pi \)[/tex] radians:
[tex]\[ B \approx 0.675 \text{ radians} \times \frac{180^\circ}{\pi} \approx 38.682^\circ \][/tex]

So, the angle [tex]\( B \)[/tex] is approximately:
- [tex]\(\sin B \approx 0.625\)[/tex]
- [tex]\(B \approx 0.675\)[/tex] radians
- [tex]\(B \approx 38.682^\circ\)[/tex]

These detailed calculations lead us to the final results for [tex]\(\sin B\)[/tex] and angle [tex]\( B \)[/tex] in both radians and degrees.