This is a 30-60-90 triangle, in which the side opposite of the 90 degrees is the longest side (2), the side opposite of the 60 degrees is the √3 (2√3 in this case), and the last side (opposite of the 30 degrees) is the (1)
2√3/√3 = 2
So the side opposite of the 30° = 2
a) the width is 2 miles
The length of the side walk is 2(a)
a = 2
2(2) = 4
b) The length of the sidewalk is 4 miles
hope this helps