Question

小学奥数——求阴影部分面积人家说 请点击查看大图 那图是真的~题没抄错.如果顶角是90度,

Answer 1

S-AEF : S-CEF = 3:2

S-ADF = S-AEF

S-AEF + S-CEF + S-ADF = 5*3/2

设S-CEF为2x,则S-AEF为3x

(2+3+3)x = 5*3/2

x = 15/16

S-总 = 5*5/2

S-阴影 = S-总 - 2*5x = 25/2 - 10*15/16 = 25/4 = 6.25