dc^2=ce^2+de^2 又有要使dc^2=ae^2+bc^2所以ce^2+de^2 =ae^2+bc^2.bc^2=6^2=36 de^2=2^2=4因为a=30°,b=90°,bc=6所以ac=12.且ac=ae+ec设ae=x 则ec=12-x所以根据ce^2+de^2 =ae^2+bc^2.就可以推出(12-x)^2+4=x^2+36所...