The formula for the circumference of a circle is the same, whatever its diameter.
Circumference = pi*diameter.
870
870
15% of 870 = 15% * 870 = 0.15 * 870 = 130.5
35% of 870= 35% * 870= 0.35 * 870= 304.5
19% of 870 = 19% * 870 = 0.19 * 870 = 165.3
All multiples of 870 are divisible by 870.
870
870
2 is not divisible by 870. 870 is divisible by 2.
870 = DCCCLXX
I see no reason why not. You may need to experiment around to find the best formula for that particular steel.
29 x 30 = 870