Question

Look at the right triangle ABC.

A student made the following chart to prove that AB2 + BC2 = AC2.

Answer 1

1. Triangle ABC is similar to triangle BDC

1. Angle ABC = Angle BDC and Angle BCA = Angle BCD
2. BC2 = AC × DC

2. BC ÷ DC = AC ÷ BC because triangle ABC is similar to triangle BDC
3. Triangle ABC is similar to triangle ABD

3. Angle ABC = Angle BAD and Angle BAC = Angle ABD
4. AB2 = AC × AD

4. AB ÷ AD = AC ÷ AB because triangle ABC is similar to triangle ABD
5. AB2 + BC2 = AC × AD + AC × DC
= AC (AD + DC)

5. Adding Statement 1 and Statement 2
6. AB2 + BC2 = AC2

6. AD + DC = AC

Answer 2

What is the flaw in the student’s proof?

Justification 4 should be “AB ÷ AD = AB ÷ AC because triangle ABC is similar to triangle ABD”.

Justification 1 should be ““Angle ABC = Angle BCD and Angle BCA = Angle DBC”.

Justification 2 should be “BC ÷ DC = AC ÷ BC because triangle ABC is similar to triangle BDC”.

Justification 3 should be “Angle ABC = Angle ADB and Angle BAC = Angle BAD”.

Answer 3

lets party!!!!!!!!!!!!!!!!!

Answer 4

tips?

Answer 5

Justification 2 should be “BC ÷ DC = AC ÷ BC because triangle ABC is similar to triangle BDC”.

Answer 6

I think justification 2 looked funny

Answer 7

what do you guys think?

Answer 8

oh crap

Answer 9

thats the wrong answer

Answer 10

Is there a drawing or can you put a picture of the chart?

Answer 11

ahhh

Answer 12

tips?

Answer 13

lol the file name...

Answer 14

pizza hut!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Answer 15

Well, sorry. I am not familiar with this kind of proof...even with the cool pizza name...maybe next time?

Answer 16

wait

Answer 17

I'm calling out the big guns now...

Answer 18

looks like we may need a scorpion vs a wraith

Answer 19

lol

Answer 20

don't worry, cal, I'm calling Zepp

Answer 21

k

Answer 22

Zepp

Answer 23

could you help me with this type of problem?

Answer 24

I did that proof last week .-. forgot how xD

lemme see

Answer 25

k

Answer 26

There's actually a guy named lolJDlol with a creeper profile pic

Answer 27

Its boss

Answer 28

and creepy at the same time

Answer 29

Basically, this student is making a proof on the pythagorean's theorem by using similar triangles.

Answer 30

yep

Answer 31

.so..

Answer 32

Justification 4 should be “AB ÷ AD = AB ÷ AC because triangle ABC is similar to triangle ABD”.

Answer 33

>thgirir

Answer 34

right?

Answer 35

3. Angle ABC = Angle BAD and Angle BAC = Angle ABD
4. AB2 = AC × AD

This is wrong.

Answer 36

Angle ABC =/= BAD

Answer 37

so justification 4 is wrong

Answer 38

k

Answer 39

:)

Answer 40

k, going to take the test

Answer 41

hope I do well

Answer 42

Have fun and do well! :)