PE,JZ.AB =AC,:. PE+PF = a (2) ...t:J£~i-8~Jvt.1L,.!ltB{ PE, PF, a 89~*J'.\~: PF-
PE
= a
iJ1t,J-
2 ~fff::::.1U~l'.81'J,t
[ff~(sl~)] sl:i\:
1. ·;LACE= 90°, CD l_AB, :. LO\.E+ LCEA = 90°, LE4.B+
LAFD = 90°,JZ. ·: AE}Jl-:5t LO\.B, :. LOlE = LE4.B, :. LCEA = LAFD,JZ.LAFD =
LCFE, :. LCEA = LCFE, :. CF= CE sl:i\:
2. ·;AB= AC, LA= 108°, :. LABC =
LC= 36° ,Jl ·:
BD f?t
LABC, :. LABD = LDBC = 18°, :. LADE= 180°-108°-18° =
54°, LCDB = 180° -36° -18° = 126° ,ft
BC :lll...t~Ijj{ CE= CD ,J)!tl
LCDE = LCED = 72°,
:. LEDB = 126°-72° = 54°, :. LADE= LEDB,Jl BD = BD, :. ,0,ABD
u:> ,0,EBD,
:. BE = AB, :. BC = BE+ CE = AB+ CD
[&~({fE~)] 1. C 2. C 3. ~)ll]:j§ 4. 3 5. ,0,ACE ~~)ll=J§%,Jll!EH~: ·; AD
f?tLBAC, :. LEAD= LOlD,JZ. ·: CE II
AD, :. LEAD= LE, LOlD
= LACE,
:. LE =LACE,:. AC= AE, :. 6ACE ~~Jlf.=J§%
6. tE~:l226ABC q:t,
·:AB=
BC =O\., LA =LB= LC,JZ.AD =BE= CF, :. AB-AD= BC-BE= Ol-CF, ~p
DB =Fr= FA,:. ,0,ADF
u:> ,0,BED
u:> ,0,CFE, :. DF =ED= FE, :. ,0,DEF ~~:lll.=J§%
7. Cl) xf,Jll!EH~:tE~:l226ABC q:t, ·;
LABC =LACE= 60°, Jl ·:
BD f?t
LABC,
:. LDBC = 30° ,Jl
CD= CF, :. LF= LCDF ,Jl ·:
LF+ LCDF =
LACE =60°, :. LF = 30°, :. LDBC = LF, :. BD = DF (2) 1:iJ
i;,(fe"BD f?tLABC"~~"BD
~ AC :lll...t.899'1~(~~)" ,Jll!EH~:l&
ffl~Jlf.=J§%89"-=~it--"1&~1:iJt;,(ftt'Jj"BD f?tLABC"
8. ~Di!!,
~* AE
JU,~ F ,it
EF =AB, ji~ DF. tE~:lll ,0,ABC q:t, ·:
AB =
AC =BC, LA= 60°, Jl ·;
CD = AE, :. AD = AF, :. ,0,ADF ~~:lll
.=J§%, :. AD =FD, LF = 60°, :. ,0,ABD
u:> ,0,FED, :. DB = DE
13. 4 R i.m
{1= Ill
iJBt
1 ft-~~J§Jt~rBffl~fJL ft-1-:ffl~rBffl:ffJ D
A B E F
(~8~)
[ff~(
sl~)] sl:it
1. f'p~: CDf'FM~ AP;@tEM~ AP ...t{&?j(~Ijj{ AC= a, CD=
DB = b; @~.§tAB ~Yr>J AB= a+2b Cl!!~) sl:i\: 2. f'F~:CDf'FM~ OC;@,f&?j( f'p LCOD = LWB = La,9!tl LCOB = 2La; @f'p LCOA = L/3; @LAOB ~Yr>l LAOB = 2La-L/3. C~Dl!lfJrlR) ( S£"i\ 2) [&~({fE~)] 1.C 2.D 3.(m~Jl'.,ri~;M)j'.EJ91LR 4.Cl)M~OP,OA (2)A,r89 K,M~ AP, B s. f'F~:CDf'FM~ OP;@tEM~ OP ...t{&?j(~Ijj{OA = a, AB= b; @&foJ~Ijj{ BC= c; @~.§t OC ~Yr>J CC= a+b-c; (00~) 6. t'tlR: PIJ'Gf'FLa, Lr 895fll, ~§tELa, Lr 895fl189P3$f'FL/3 7. t'tlR :7'6f'F-~~.§t BC= b, .pJ.:5tjJ1Jt;,(,~ B, C ~[m,C,,, t;,( a 89*~-*11@W3'.tr,~ A,ji~ AB, AC,9!tl6ABC ~Yr>J 8. t't7R:7'6f'F~.§t BC= a, f'&J§-%£U~ B, Cjg]]j!Af'FJfJ:5t£U~rLa, Li9,ep-aJf'FiliJ!t=JfJ% illfit 2 ftBfflJfJ(l{Jift:$}~ [ffM( sl~) l ~it 1. mlR :5tf'l::La 89¥-%~ ,1,~J ~ La, -lllf'F ~ La a9-1JZ-:5t~epey1,~J LAOB= ! La ~it 2. 00~,icM~ BP ~M~ CQ fflxr,i,~ D, LC 89>'~JfJjgLACE ,!J!UER nx;a{]i]tft§jgLBDC,'t~LA a{]~*jg LBDC = ~ LA,fll!EB~: ·: BP -112-% LABC, CQ -112-::fr LACE, :. 2LDCE = LA+2LDBC,.:R LDCE = LDBC+ LBDC, :. LBDC = ~ LA [&~('(JE~)] 1. B 2. A 3. i!li!li!l 4. f'FB~JfJB9¥-:5t~ s. ~ 6. f'l::00~,0D_l OE, fl!! EB~:·: LAOB + LIDC = 180°, .:R OD -112-::fr LAOB, OE -112-::fr LIDC, :. 2LWB + 2LIDE = 180°, ep LWB + LIDE = 90°, :. LWE = 90°, :. OD _l OE 7. Cl) f'l::00~ (2) ·; BG-112-::frLABC, :. LABC = 2LGBC,.:RLABC = 2LAED, :. LAED = LGBC,.:R ·: AE // BC, :. LEAF= LC, .:RAE= BC,: • .6AEF (/) .6CBG, :. EF = ffi 8. Cl)·: AB //CD, :. LCMA = LBAM, EBR;/;]f'F7*1tT~:AP -112-::fr LO\.B, :. LCAM = LBAM, :. LCMA = LCAM, .:R LACD = 114°, :. LM4.B = LCAM = LCMA = ~ x (180°-114°) = 33° (2) ·: CN _lAM, :. LCNA = LCNM,.:RLCMA = LCAM, CN = CN, : • .6ACN (/) .6!vICN illfit 3 ~,:t~Bffl.'i'MtBffl.a~((.J:ji;~ [ffM( sl~)] ~it 1. ~ ~it 2. f'l::7*:CDf'FM~AP;®tEM~AP J:~IlitAC = b; ®M ,#, A f'FM~AP a{]*~AT;@tl: AT l:~IlitAB =a,~~ BC;@.6ABC jgEJr>)<:f'Fa{J][JfJ.=::JfJ %. GmOOEJrlR) a b ------f-- A-'---+--_____,,f--C-P (sfj\ 2) [&ffi(ift~ll 1. o 2. 1:.>1~ 3. @ 4. ~ s. ~ 6. :t.mm 1. :tinm A a a a b h h h B D c (~6)m) illfit 4 ftBffl~¥Jt((.J:ji;_aift5}~ [ffM( sl~)] ~it 1. ~ ~it 2. f'l::7*:CDf'FM~ BP;®tl:M~ BP _t~}lkBC = b; ®fl:: ~~BC 89*][¥-::fr~MN ;@~,#, B jgOO,C,,,~ a a{J*:1g¥-1:£1!!If5Jll:XMN r,#,A,~~ AB,AC; @.6ABC jgEJr>)<:fpa{]=ft§%. (00~)