Question

Could someone help me with Geometry.

Answer 1

Could someone clarify this to me.

Answer 2

so i think that you are right using proportionalitie of corresponding sides

yes ?

Answer 3

@jhonyy9 @horsegirl27 @phi

Answer 4

All triangles are right triangles ... there are no non right triangles

Answer 5

no, i mean in the picture, there is one right triangle and the other isn't.. correct?

Answer 6

All 3 right triangles

Answer 7

How do i prove the Pythagorean theorem there? i know about it but i just don't know where to start. we will use substitution method and distributive property. but can't tell where to begin

Answer 8

We can rule out two of the choices, because the proportions are wrong.

the answer is either choice A or C

I don't know a good way to answer this except if you have seen this proof.
see Proof #6 in
http://www.cut-the-knot.org/pythagoras/

Answer 9

\[\triangle ABC \sim \triangle DAC \sim \triangle DBA\]
from triangles 1 and 2:\[{BC \over AC} = {AC \over DC}\] ... rewrite: \(\color{blue}{BC \cdot DC = AC^2}\)

from triangles 1 and 3:\[{BC \over BA} = {AB \over DB}\] ... rewrite: \(\color{blue}{BC \cdot BD = AB^2}\)

Answer 10

add them up :
\[\large BC \left( BD+DC \right)=AB^2+AC^2\]

BD + DC = BC

Answer 11

You are amazing, Thanks so much @PaxPolaris