Solve this: ABACL
ABAC
in SOAP and AOBC,
ZAOO zBOC
ZAI;O
AOAD AOBC
OA 0B and OC = 00.
Example is a
If zA08 1260 and Z poc - zQCD =
Solution. AP and BQ to meet at R
A ABD-ABAC.s0ZA0b4
In BRIX, z RCD
(each angle 52')
(sides opp. equal angles are equal)
ZRAB-2RDC
*milady, ZRCtY
zRAB ZRBA
AR-RB.
(corres us. AB
AD = AR-DR RB - CR
ABCD is an isosceles trapezium.
(Example 27)
ZOAB
ZOAB*
LDAC. 520-270 z 250
ZACB z ABC- 1800
1800-270-52
101.'.
Exercise 12.1
(sum
5. (a) In i iguß
figure
diagona
z ABO=
7. figure
BE
(b) figure
(c) In figure
ZOAB
(a) In figu
In
L If two angles a quadrilateral are 400 and 1100 and the Other two
3 : 4. fir-Id these
Z Ifthe angles mwirilateral, taken in order, are in the ratio
a trapezium.
3. an angle • pamWvarn is two-thirds of its adjacent angle, find
4. (a) In figure (1) *v.' Wow, ABCD is a parallelogram in
ZDBC COB and ADB.