Look at the right triangle ABC below: B
A
A student made the following chart to prove that AB2 + BC2 = AC2:
Statement
Justification
1. Triangle ABC is similar to triangle BDC
1. Angle ABC = Angle BDC and Angle BCA = Angle DCB
2. BC2 = AC x DC
2. BC ÷ DC = AC ÷ BC because triangle ABC is similar to S
triangle BDC
is 3. Triangle ABC is similar to triangle ADB
3. Angle ABC Angle BAD and Angle BAC = Angle ABD
4. AB2 = AC x AD
4. AB ÷ AD = AC ; AB because triangle ABC is similar to
triangle ABD
5 AB2
BC2 = AC x AD + AC X DC = AC
(AD + DC)
5. Adding Statement 2 and Statement 4
6. AB2 + BC2 = AC2
6. AD + DC = AC
What is the flaw in the student's proof? (1 point)