Ask your own question, for FREE!
Mathematics 10 Online
OpenStudy (anonymous):

Write a paragraph proof to show that triangle ABC is congruent to triangle DEC Given: line AC is congruent to line DC and line BC is congruent to line CE

OpenStudy (anonymous):

|dw:1398413032246:dw|

OpenStudy (anonymous):

So I already know that Statement Reason 1. Line AC is congruent to line DC and line BC is 1. Given congruent to line CE Now how can I finish this proof paragraph ?

OpenStudy (anonymous):

@ganeshie8 @geerky42

OpenStudy (wolf1728):

Angle BCA = Angle DCE (Vertical Angles are equal) You now have 2 sides and an included angle being equal in 2 triangles. According to the theorem (side-included angle-side) the triangles are congruent.

OpenStudy (anonymous):

So statement 2 would be <BCA = <DCE ?

OpenStudy (anonymous):

And the reason would be SAS ? I'm confused ...

OpenStudy (wolf1728):

Yes - they are vertical angles

OpenStudy (wolf1728):

The reason the angles are equal is that vertical angles are always equal. The triangles are congruent because 2 corresponding sides and an included angle are equal.

OpenStudy (anonymous):

so just put vertical angles ?

OpenStudy (wolf1728):

vertical angles are equal

OpenStudy (anonymous):

Ok thanks and there is more right ?

OpenStudy (anonymous):

statement 3 ?

OpenStudy (wolf1728):

No. All that you had to prove is 2 corresponding are equal and the included angle is equal. Statement 3 would be s-a-s (side angle side)

OpenStudy (wolf1728):

left out the word SIDES 2 corresponding SIDES are equal

OpenStudy (anonymous):

i thought sas was a reason

OpenStudy (wolf1728):

Yes - that's why I said it was statement 3

OpenStudy (anonymous):

ok so i'm confused now we dnt have an answer for statement 3

OpenStudy (anonymous):

And should line BA is parallel to DE be another statement ?

OpenStudy (wolf1728):

No- if we do this step by step BC = CE and AC = CD (given) Angle BCA = Angle DCE vertical angles are always equal. Triangle ABC is congruent with Triangle DCE - s-a-s

OpenStudy (anonymous):

ohh ok i see now

OpenStudy (wolf1728):

And here's how Wikipedia defines side angle side: SAS (Side-Angle-Side): If two pairs of sides of two triangles are equal in length, and the included angles are equal in measurement, then the triangles are congruent.

OpenStudy (anonymous):

Can you answer my other question about line BA and DE please ??

OpenStudy (wolf1728):

I think they are parallel but you don't need to use that for the proof of the triangles being congruent.

OpenStudy (anonymous):

Okay thanks so much ! You were a big help

OpenStudy (wolf1728):

Thank you :-)

OpenStudy (anonymous):

@shubhamsrg

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!