1、 1 2 3 1 2 1 (2) 1. ( ) O 2 AB O P AB 1 OP 2 AB ( ) A B B A O P C P AB B A O P E F OP AB OP 1 OP 2 OP 1 P A B OP OA OB 2 sin OAB sin OBA 1 2 OAB OBA AOB AEB 1 2 AOB E F F AB C 2. AC BE O AD BE F O A ABE B ACF C ABD D ADE B A B E O O ABE F O O ACF A B D O O ABD A D E O O ADE B 1. O O AB AB AB A B 2.
2、O AB O P AMB APB A 3. ABD O AB C O BCD ( ) A. B. C. D. 4. O ABC BOC 80 BAC ( ). A.40 B.100 C.40 140 D.40 100 5. ABCD O ADC AOC A 1-5 DDBCA 1. AB O CD AB E AB=8 CD=6 BE=_. 7 4 OC AB O CD AB E CE= CD 2 1 =3 7 3 4 2 2 2 2 CE OC OE , BE= 7 4 . 7 4 . 2. O AB CD ACD=40 BAD=_ . 50 B= ACD=40 AB O ADB=90 BAD
3、=90 40 =50 50. 1. O OAB 45 O AB OE 2 cm, AB cm B A E O2. AB O C O BC 6 AB 10 OD BC D OD _ 3. C A B 100 150 ACB _ . 4. O ABCD A BOD 1 4 4 4 25 130 1. AB O P A B BP C PC=PB D AC PD PO. 1 CDP POB 2 AB=4 AOPD OD PBA BPDO . D O B A CP A O C B D (1) O P D AB BC AC DP OB DP=OB CD OP CD=OP. CPD= PBO. CDP PO
4、B , , CP PB CPD PBO PD OB CDP POB SAS . (2) 4 P O AC BC AB AOPD P G AOPD S AO PG PG AOPD AOPD S AO PG =4 BPDO BP=OB=2 PBA= BPDO . P C O A B D G2. 2016 1 1 A B C AB BC ABCD 2 2 ABCD AB O AC BD ABCD 3 3 Rt PBC PCB BC 11 tan PBC 5 12 A BP AB 13 PC D ABCD CD 1 1 2 2 2 AC BD AB O ADB ACB Rt ADB Rt ACB ,
5、, AB BA BD AC Rt ADB Rt BCA AD BC AB O AB CD ABCD 3 3 D . CD AB D D1 CD1 AB 13 AD BC 11 D D2 D3 AD2 AD3 BC 11 A AE BC AF PC E F BE x tan PBC 12 5 AE 12 5 x Rt ABE AE 2 BE 2 AB 2 2 22 12 13 5 xx x1 5 x2= 5 BE 5 AE 12 CE BC BE 6 AECF AF CE 6 CF AE 12 Rt AFD2 2 2 2 2 22 11 6 85 FD AD AF 22 12 85 CD CF
6、FD 32 12 85 CD CF FD CD 13 12 85 12 85 1. 1 O 4 2 AB C AB 20m AB=80m 4 2. ABCD AC BD E F BA EF EF O DC D G AD EF GF I H 1 FDE 2 FACD 3 G DC DF=FI AC=2m BD=2n O ABCD H I D G C A O E F B 1. 1 1 1 O . 2 OA AB OC AB D 2 C AB OC AB AD=BD= 1 2 AB=40 O r OA=r OD=OCCD=r20 Rt OAD OA 2 =OD 2 +AD 2 r 2 =(r 20)
7、 2 +40 2 r=50 50m 2 2. 1 EF O FDE 2 FACD ABCD AB CD AC BD AEB= FDE AC FD FACD 3 GE Rt DEC G CD EG=DG DG =EG 1= 2 EF O FGE FG EG G DC E AC GE DAC EG AD FG AD FHD= FHI DHF IHF FD=FI ABCD AE=CE=m BE=DE=n FACD FD=AC=2m=FI FD AC 3= 8 3= 4= 7 7= 8 EI=EA=m Rt FDE FE FD DE 3m 2m n n= 5m O S = 2 3 2 m = 9 4 m ABCD S = 1 2 2m2n=2mn=2 5m O S ABCD S = 9 4 2 5m 95 40
