Is there a formula to calculate the height (a) of a regular hexagon when you know it's width (b)?

Is it possible to adapt this formula to a sum like :
b = a + a*x
Is there a formula to calculate the height (a) of a regular hexagon when you know it's width (b)?

Is it possible to adapt this formula to a sum like :
b = a + a*x
Wikipedia article on hexagons states that a height-to-width ratio of a regular hexagon is 1:1.1547005.
So although trigonometry can do this, you can also use:
a = b * 0.8660254
d = sqrt(3) / 2 * D. In this context d is the value called a in the OP's post, and D is the value called b. If you evaluate sqrt(3) / 2 it comes out to 0.8660254
– dgnuff
Jan 27 '22 at 19:59
Draw a line from the centre to the upper left vertex. You now have a right angled triangle and some trigonometry will soon allow you to relate $a$ to $b$.