Wing Aspect Ratio
In the simplest rectangular wing planform area, the aspect ratio is defined as aspect ratio, AR = (span, b)/(chord, c). For a generalized trapezoidal wing planform area:
aspect ratio, AR = (b x b)/(b x c) = (b2)/(SW) (3.36)
3.7.3 Wing Sweep Angle, Л
The wing quarter-chord line is the locus of one fourth of the chord of the reference wing planform area measured from the LE, as shown in Figure 3.31. The wing sweep is measured by the angle of the quarter-chord line extended from the line perpendicular to the centerline.
3.7.4 Wing Root (croot) and Tip (ctip) Chord
These are the aerofoil chords parallel to the aircraft at the centerline and the tip, respectively, of the trapezoidal reference area.