try finding the slope of the diaganols

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- 10-03-2002red_baron
try finding the slope of the diaganols

- 10-03-2002NavyBlue
Here's a diagram I drew.

A (0, b)----------------C (a+c, b)

B (-c, 0) )----------------D (a, 0)

4 different points on the graph. Point B is in quadrant II. The other points are in quardant I.

I'm trying to find the slopes of AD and BC. If the slopes are negative reciprocal, then they must be perpendicular. Is there another way to prove that the diagonals are perpendicular without using their slopes? - 10-03-2002red_baron
finding the slopes is the easiest way i know of... btw what grade are u in?

- 10-03-2002moiRe: ParallelogramQuote:

*Originally posted by NavyBlue*

**How do you prove the diagonals of a parallelogram are perpendicular to each other, meaning that the diagonals' slopes are negative reciprocal of each other.**

- 10-03-2002Eibro
I don't really see getting help as cheating... it's the same as answering questions on the C++ board about programming.

Try #math on DALnet (irc) for your math problems, they're avid about not doing peoples homework for them (kinda like us)... but they're friendly and willing to help if you want help and not just an answer. - 10-03-2002kermi3Quote:

I don't really see getting help as cheating... it's the same as answering questions on the C++ board about programming.

I don't see how it's not cheating...

Every honor code I've ever been under has been under has been to the effect of:

Quote:

I have not (nor will I) given or recieved unauthorized aide on this assignment

- 10-03-2002CshotQuote:

Bah you win Cshot. But when proving a therom like this you shouldn't use a "special kind". You should use the most generic you have.

Can't think right now but the only 2 parallelograms that have that property is the square and rhombus. Hope I'm right. - 10-04-2002Govtcheez
> is the square and rhombus.

And since a square*is*a rhombus, that only leaves one, doesn't it?

The diagonals of a parallelogram are only perpendicular if it's a rhombus, Navy - 10-04-2002Cshot
Good point cheez. Been so long since I've taken geometry...(shuts out that part of memory)