CD bisects

Question

CD bisects <ADB and ADB  is an isosceles triangle. What is another true statement that proves that ADC is congruent to BDC?
http://www.thelearningodyssey.com/Assess/DPT/QIEImagesStorage/AQ13G/AQ13GE_GE422_17_stem1_5.gif
 
A.	AC IS CONGRUENT TO BC- definition of midpoint
	B.	ACD IS CONGRUENT TO BCD- all right angles are congruent
	C.	CD IS CONGRUENT TO CD- Reflexive Property of Equality
	D.	There is not enough information to prove the triangles true.

cwrw238 · Answer

which one do you think it is?

anonymous · Answer

I thought it was A but I've always sucked at this part so I don't trust it...

cwrw238 · Answer

you know that angles ADC and BDC are congruent and side AD is congruent to side BD

cwrw238 · Answer

you can prove congruency by SAS - 2 sides and included angle so you need another side

anonymous · Answer

So it would be B) because it states that all right angles are congruent?

samara8954 · Answer

help me

cwrw238 · Answer

another side is needed 
what sides is common to the 2 triangles?

anonymous · Answer

CD?

cwrw238 · Answer

- its a part of the 2 triangles

cwrw238 · Answer

yes

cwrw238 · Answer

C is correct

anonymous · Answer

Thank you so much! :)

cwrw238 · Answer

yw - I dont see why they use 'reflexive property of equality'  - why not just they  CD is common to triangles ADC and BDC  - much simpler