Answer:
Explanation:
Part b: Find the length of the sidewalk. The walk is the hypotenuse of a right 30-60-90 triangle with horizontal side 2√3. Using the 30° angle as the reference angle, we get the following from the definition of the cosine function:
 
cos 30° = adj / hyp, or:
 
 √3 2√3
 ------- = --------
 2 hyp
This simplifies to
 1 2
 -------- = -------
 2 hyp
Cross multiplying results in: hyp = 4. The sidewalk length is 4 miles.
a. The width of the park can be found using the sine function, the now-known hypotenuse and the 30° angle:
 1 opposite side
sin 30 degrees = ----- = ------------------------- or 2(opp side) = 4.
 2 4
Then the opp side, which is the width of the park, is 2.