It has become customary to compute the MAC of the right and left wings separately. In this case, the right wing is defined by two chords.
&chord y=0, xle=0, c=400/ &chord y=1000, xle=600, c=200/
giving the following result.
MEAN AERODYNAMIC CHORD DEFINED BY ex1a.nml # y xle c xte 1 0.00000 0.00000 400.00000 400.00000 2 1000.00000 600.00000 200.00000 800.00000 area of wing= 300000.0000 length of MAC= 311.1111 y of MAC= 444.4444 xle of MAC= 266.6667 xte of MAC= 577.7778 x of c/4 of MAC= 344.4444
and the chord is shown on the following figure.
Of course, there is an image chord for the left wing.