There is no solving of this problem. This is the equation for energy-mass equivalence as derived by Albert Einstein. If you have values for different aspects there could be some solving.
Central angle of a regular polygon:
Ф = 360° : n.
If n=12: Ф = 360° : 12 = 30°
At the angle of rotation Ф = 30° the image of the polygon will coincide with the preimage.
Answer:
that is the nearest thousands decimal place
Fractions, ratios, and percents all interconnect. For example, 50% = 1/2 = 1:2