ページ1:

整理△的特殊性質
①子母性質(彈珠法) ②內分比性質(角平分线)
双直角性質
a
b
e
h
d
D
C
B
LUX
A
40 DE=DF
B
Le = cxd
Sev
a² = cx (C+d)
b = dx (c+d)
why?
AABD ACAD
AD = BD = CD = AD
= e = c = d = e
ǝ ev = cx d
*其它類推!!!
= AC = BD DC
= AB = AC
why 2
面積法證明
a² ABD as ACD = BD = DC (13)/2
ABXDEX = = ACX DFX ≤
=AB=AC(等高)
1. BD :DC = AB = AC #

ページ2:

85 T N H H H u n n n n n
③外分比性質(易忘)
+DI
E
B
E
補B5C3
→x外角
D
④ 國內外業性質(彈珠法)
axd=bxc
7
a b
記法:
同內分比
AB AC BC = CD
v
azbx(b+c)
ax (a+c)
bibt d