If we have a semicircle of diameter AB (with length 1) and center O, then we can find the approximate value of the chord AC, by the following formula,where $x$ represents the value of the angle AOC
$\sqrt\frac{1}{\left(\sqrt[90]\frac{10{\pi}}{\sqrt{50}×4}^{(2x-90)}×\left(\frac{90}{x}-1\right)×\sqrt{ 2}+1\right)^2+1}$
For example if the value of $x=60$, we will get 0.4999469.. So , my formila gives an approximate value of the chord. There is formula similar to mine, in the literature?