Explanation:
I guess it means we need to calculate the height of the green dot on the bicycle wheel that moves as the wheel turns by a certain radial distance.
since the circumference of a circle is 2×pi×r, the circumference for a circle with radius = 1 is simply 2×pi (ft in this case).
pi/2 = 90° or a quarter rotation.
pi = 180° or a half rotation.
3×pi/2 = 270° or 3 quarter rotation.
2×pi = 360° or a full rotation.
the height starts at 6ft, and can go up 2 more ft (the diameter of the wheel) to 8 ft.
so, the table is
0 6
pi/2 7 (6+1)
pi 8 (6+2)
3×pi/2 7 (6+2-1)
2×pi 6 (6+2-2) back to the starting height
so,
a = 6
b = 7
c = 8
d = 7
e = 6