Substitute the area of the sector and radius at turn B into the area of a sector formula and solve for the central angle measure.

[tex]\[
\begin{array}{l}
918 \pi = ( m \angle B) \cdot 9 \pi \\
918 = ( m \angle B) \cdot 9 \\
102 = m \angle B \\
\end{array}
\][/tex]

So, the measure of the central angle, [tex]$\angle B$[/tex], is [tex]$102^{\circ}$[/tex].

Question 3:
Use the value of the central angle you found in question 2 and determine the length, in miles, of the track around turn B. Round your answer to three decimal places.



Answer :

To determine the length of the track around turn B, we need to use the formula for the length of an arc of a circle. The formula is:

[tex]\[ \text{Arc Length} = \left(\frac{\text{central angle}}{360}\right) \times 2 \pi \times \text{radius} \][/tex]

From question 2, we know the central angle ([tex]\(\angle B\)[/tex]) is [tex]\(102^\circ\)[/tex] and the radius of the circle is given as [tex]\(9\)[/tex] miles. Here, [tex]\(\pi\)[/tex] (Pi) is a constant approximately equal to 3.14159.

Step-by-step solution:

1. Substitute the values into the arc length formula:
[tex]\[ \text{Arc Length} = \left(\frac{102}{360}\right) \times 2 \pi \times 9 \][/tex]

2. Simplify the fraction:
[tex]\[ \frac{102}{360} = \frac{51}{180} = \frac{17}{60} \][/tex]

3. Substitute back into the formula:
[tex]\[ \text{Arc Length} = \left(\frac{17}{60}\right) \times 2 \pi \times 9 \][/tex]

4. Multiply the constant terms:
[tex]\[ \text{Arc Length} = \left(\frac{17}{60}\right) \times 18 \pi \][/tex]

5. Further simplify this:
[tex]\[ \left(\frac{17}{60}\right) \times 18 = \frac{17 \times 18}{60} = \frac{306}{60} = 5.1 \][/tex]

6. Now use this with [tex]\(\pi\)[/tex]:
[tex]\[ \text{Arc Length} = 5.1 \pi \][/tex]

7. Multiply by [tex]\(\pi = 3.14159\)[/tex] to find the numerical arc length:
[tex]\[ \text{Arc Length} = 5.1 \times 3.14159 \approx 16.0221 \][/tex]

So, the length of the track around turn B is approximately [tex]\(16.0221\)[/tex] miles. Rounding to three decimal places, we get:

[tex]\[ \text{Arc Length} \approx 16.022 \][/tex]

Therefore, the length of the track around turn B is [tex]\(16.022\)[/tex] miles.