#	Calculate areas for `<metrics>` section
##	Calculate horizontal tail area:

*	basic shape: mirrored trapezoid
*	ref. 3:
	*	span: 3.170 m
	*	root chord: 0.780 m
	*	tip chord: 0.418 m

*	area 	= span * 0.5 * (root chord + tip chord)
			= 3.170 m * 0.5 * ( 0.780 m + 0.418 m )
			= 1.90 m^2

##	Calculate vertical tail area:

*	basic shape: trapezoid
*	ref. 3:
	*	root chord: 1.200 m
	*	height:	1.600 m
	*	tip chord (estimate): 0.571 m
*	area	= height * 0.5 * (root chord + tip chord) = 1.6 m * 0.5 * ( 1.2 m + 0.571 m ) = 0.8 m * 1.771 m = 1.42 m^2
