drilateral ABCD, the bisector of ZC andLD intersect at OProve that 2CO

1.	drilateral ABCD, the bisector of ZC andLD intersect at OProve that 2COD =-(ZA + 2B)
Answer» Angle COD= 180°- 1/2angle C-1/2 angle D=180°-1/2(angle C+D)----------(1) Angle (A+B+C+D)=360° AngleC+D= 360°- AngleA- angle B--------------(2) Substituting (2) in (1) Angle COD= 180°-1/2(360°- angle A- Angle B) Angle COD= 180°-180°+1/2 Angle A + 1/2 Angle B= 1/2(Angle A+ Angle B) thanks

drilateral ABCD, the bisector of ZC andLD intersect at OProve that 2COD =-(ZA + 2B)

Answer»

Angle COD= 180°- 1/2angle C-1/2 angle D=180°-1/2(angle C+D)----------(1)

Angle (A+B+C+D)=360°

AngleC+D= 360°- AngleA- angle B--------------(2)

Substituting (2) in (1)

Angle COD= 180°-1/2(360°- angle A- Angle B)

Angle COD= 180°-180°+1/2 Angle A + 1/2 Angle B= 1/2(Angle A+ Angle B)

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