Question

Zinnia wrote the following proof to show that the diagonals of rectangle ABCD are congruent.

Zinnia’s proof:
Statement 1: In triangle ADC and BCD, AD = BC (opposite sides of a rectangle are congruent)
Statement 2: Angle ADC = Angle BCD (angles of a rectangle are 90°)
Statement 3: DC = DC (reflexive property of equality)
Statement 4: Triangle ADC and BCD are congruent (by ASA postulate)
Statement 5: AC = BD (by CPCTC)
Which statement in Zinnia’s proof has an error?

Statement 1

Statement 4

Statement 3

Statement 2

Answer 1

k

Answer 2

tips

Answer 3

choice 2 looks promising

Answer 4

Any particular reason why?

Answer 5

wait

Answer 6

I just saw something

Answer 7

Statement 4

Answer 8

ASA postualte

Answer 9

That seems to prove the reason

Answer 10

what say you?

Answer 11

It uses the ASA postulate. Look at the triangles Zinnia is using. What should Zinnia use instead?

Answer 12

ahh

Answer 13

SSS

Answer 14

lolz

Answer 15

I should have read the problem more carefully

Answer 16

SSS? I think not. We use the fact that the triangles are congruent to show that the thirds side is congruent.

Answer 17

ehh, AAS?

Answer 18

We have AD=BC, angle ADC = angle BCD, and DC=DC.

Answer 19

SAS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Answer 20

k

Answer 21

Sorry, I'm tired

Answer 22

I've been working since 8:00 A.M.-9:00 P.M.

Answer 23

Working on this stuff all day?

Answer 24

yeah...

Answer 25

almost done though

Answer 26

only chapter 10 and final now

Answer 27

I've done all of the assignments

Answer 28

That's a long time o.O. You should do the final with the OS tab closed though.

Answer 29

k

Answer 30

when I actually take the test, though

Answer 31

mabye I'll one or two more today and save the rest for tomorrow