與monseigneur的解法類似,利用相似三角形帶來的比例性質
18/(x+18) = S_AEF/S_ACD = (AE*AF)/(AC*AD)
= AE/(AE+EC) * AF/(AF+FD)
= AG/(AG+BC) * AG/(AG+BD)
= (BH/2) / (BH/2+BH/3) * (BH/2)/(BH/2 + 2*BH/3)
= 9/35
因此
18/x = 9/(35-9) = 9/26
x = 52
亦解
所有跟帖:
• 好!此題有多種解法 -萬斤油- ♂ (0 bytes) () 12/21/2023 postreply 21:07:06
• 漂亮! -monseigneur- ♂ (0 bytes) () 12/21/2023 postreply 21:35:24