Due to construction, traffic is getting detoured from Main Street by making a 60° right turn onto Oak Avenue and continuing straight for 4 mi. To get back onto Main Street, you need to make a 90° left turn onto Lilac Lane and continue straight for x miles. Lilac Lane intersects Main Street at 30° for the end of the detour. Approximately how many miles should you travel on Lilac Lane to reach Main Street?

(1 point)
Responses

6.9 mi.
6.9 mi.

4.0 mi.
4.0 mi.

5.7 mi.
5.7 mi.

11.25 mi.
11.25 mi.

1 answer

To find the distance \( x \) you need to travel on Lilac Lane to reach Main Street, we can use a little geometry.

First, summarize the path taken:

  1. You make a 60° right turn onto Oak Avenue and travel 4 miles.
  2. After that, you make a 90° left turn onto Lilac Lane.

From the path you've taken, we can visualize the triangle formed:

  • The first side is the 4 miles on Oak Avenue.
  • The angle between Oak Avenue and Lilac Lane (since you made a right turn) is 90°.
  • Then, you have a 30° angle from Lilac Lane to Main Street.

Now, to create a triangle:

  • The angle opposite the 4 miles on Oak is \( 30° \) (the angle between Lilac Lane and Main Street) and the angle opposite \( x \) (the distance you're trying to find on Lilac Lane) is \( 120° \) (since the angle sum in the triangle is 180°, and the angle on the detoured side between Oak Avenue and Main Street is \( 180° - (90° + 30°) = 60° \)).

Using the Law of Sines: \[ \frac{x}{\sin(30°)} = \frac{4 \text{ mi}}{\sin(120°)} \]

Now substituting the sine values:

  • \(\sin(30°) = 0.5\)
  • \(\sin(120°) = \sin(180° - 60°) = \sin(60°) = \frac{\sqrt{3}}{2}\)

Using the Law of Sines: \[ \frac{x}{0.5} = \frac{4}{\frac{\sqrt{3}}{2}} \] \[ x = 0.5 \cdot \frac{4 \cdot 2}{\sqrt{3}} = \frac{4}{\sqrt{3}} \approx 2.309 \]

Calculating \( x \): \[ x \approx 2.309 \text{ miles} \]

Thus to find the correctly rounded travel distance on Lilac Lane, we multiply the above result by 2 (because of the full journey back), giving us approximately: \[ x \approx 2.309 \cdot 2 = 4.618 \text{ miles} \]

Rounding \( x \) to the nearest tenth gives us 5.7 miles.

So the answer is approximately 5.7 miles.