MSSE
MADE IN
DEN J
70.5
則
| _ ABC |, sin A = sin Beos C – cos BsinC, AB=10, CA=13,
則BC =
=
·Siul B-c)
252
3
6. 如圖一、<E、LF 均為直角,BE=1,BF=3,∠EAF = 60°
!!!! TB = 40112√3
12+167√3)2
=1+ 36+12√3+3 = 40+1253
7. 如圖二、4BCD 為長方形,AB=6
BC=3DE=2,
△APF為等腰直角三角形,<EPF=0,則rand=
8. 如圖三,ABCD為任意四邊形,ABDE為平行四邊形,且AAEC中,
LACE=45", ZAEC-60°, AAEC 4
圖三
圖二
D
E
B
A
P
C
E