Respuesta :

∠X = 180 - 68.2 · 2 = 180 - 136.4 = 43.6°

XY/sin(68.2°) = YZ/sin(43.6°) 
XY/0.9285 = 20/0.6896
XY/0.9285 = 29
XY = 29 · 0.9285 = 26.93 cm

XY = XZ = 26.93 cm