Add FromDiameter to Area.extra

[gojanpaolo]

Can we add something like:

public static Area FromDiameter(Length diameter)
{
	return Math.PI * diameter * diameter / 4;
}

I was hesitant to suggest this before but I saw similar functions for PowerRatio which uses some kind of computation to convert from one unit to another.

[angularsen]

Sure, we have several of these from before so I'm fine with this.

[angularsen]

On second thought, maybe it should be named FromCircleDiameter() to be very clear what is about? At least I find that slightly more informative.

[angularsen]

...aaand, consider adding the radius variant while at it. :-)

[gojanpaolo]

You bet! :)