Question

CC

想問(1)、(2)為什麼能得出PR:RC=3:4、BR:RQ=3:2呢？謝謝

3
+
7
5
類題 10 如右圖,點P在 AB 上,點Q在 AC 上, BC 與 CP 交於R,
AR 23 AB+ŻAC
求:
AQ
ABPR 9
(3)
OC 2
ACOR 8
(1) # AR = AB+ ŽĀC= 4
3
(由
=得
AC,得二
14 AB = 4 AP AP = 107
-
- ::
7 AB, 19 AP-7
5
Q
=
(1)
AP
PB
7
3
(2)
=
=
R
B
+
=
AP+
PB
3
5
.-. PR : RC = 3:4
37
(2) AR
<16+ AC = = 46 + 40,得AC-30 .40 = =AC,得
AB
19
AQ
II
得
QC
5
2
... BR : RQ = 3:2
1
* PR BR sin ZPRB
2.
ACOR
- RC x RQ x sin ZCRQ
2
X
ABPR
-
(3)
PR
RC
X
BR
RQ
339
4 2 8
X
X

向量