AB=2DA=2CD=10 (AB是矩形的对角线,两对角线互相平分)
CA^2=AB^2-BC^2=100-64=36
CA=6
sin∠ACD=sin∠CAD=8/10=4/5
tan∠ACD=tan∠CAD=8/6=4/3
cos60°+sin45°-tan30°
=1/2+(根号2)/2-(根号3)/3
=[1+(根号2)]/2-(根号3)/3 [无法再化简]
3tan30°-根号3sin60°+2cos45°
=根号3-(根号3)(根号3)/2+2*(根号2)/2
=根号3-3/2+根号2
=根号2+根号3-3/2 [无法再化简]