To find coterminal angles for an angle, β, given in radians use the following formula:
coterminal angle = β + 2πk
where k is an integer {..., -3, -2, -1, 0, 1, 2, 3, ...}
Negative Coterminal Angle: k = -1
NCA = π/5 + 2π(-1)
= -9π/5
Positive Coterminal Angle: k = 1
PCA = π/5 + 2π(1)
= 11π/5
The following answers are just one of many possible answer... you have infinite number of choices for k.

I don't see any question there ... just a bunch of pretty rulers.
I'm going out on a limb here, and I'm gonna assume that the question is "Identify the number to which the arrow on each ruler is pointing.".
If that's the question, you're welcome. If not, ignore everything I'm about to say.
Orphan ruler on page-1: 6 and 1/4
Rulers on page-2, starting at the top and working down:
6 and 3/8
1
3 and 5/8
2 and 1/2
7 and 3/4
4 and 7/8
5 and 1/8
9 and 1/2 .
If these answers are not helpful, remember: I'm the one who had to invent the question, and for the question that I invented, these answers are all correct !
D= 11.40
The distance between the coordinates is 11.40 units.
51,000
5 in the ten thousands,
The thousands value is 1, the hundreds is 4 (less than 5 so we round down)