(1)對於類似的圖形,面積比等於對應邊長比的平方s 1:S2 = A ^ 2/B ^ 2?
(2)s 1 \u S2 \u S3 \u S4 =?a^2︰b^2︰ab︰ab?;?
③S3 = S4?;?
(4)S1×S2=S3×S4(推導自S1/S3=S4/S2)?
(5)?AO:BO=(S1+S3):(S2+S4)