Questions about the world of GMAT Math from other sources and general math related questions.
yamini
 
 

how to know whether line goes through vertex(0,0)

by yamini Thu May 10, 2007 11:34 am

In case of co-ordinate plane if we know slope-intercept equation of line y=mx+b then
how to find whether it goes through center (0,0) ?

what is the equation for polygon external angles sum? For internal angles (n-2)180. (n is no.of sides).

In case of the traingles or polygons if they say as "measure of the sides" - does it mean length of the side or angle of the side?
Saurabh Malpani
 
 

Re: how to know whether line goes through vertex(0,0)

by Saurabh Malpani Thu May 10, 2007 11:48 am

Yamini,

1) In case of co-ordinate plane if we know slope-intercept equation of line y=mx+b then how to find whether it goes through center (0,0)

Ans: if the intercept "b" is equal to zero then the line passes through origin else not.

2) what is the equation for polygon external angles sum? For internal angles (n-2)180. (n is no.of sides).

Ans: For any polygon the sum of external angles is always equal to 360

3) In case of the traingles or polygons if they say as "measure of the sides" - does it mean length of the side or angle of the side.

Ans: I am not sure about this but I would have gone with the lenght of the side.

I hope it helps

Thanks
Saurabh Malpani



yamini Wrote:In case of co-ordinate plane if we know slope-intercept equation of line y=mx+b then
how to find whether it goes through center (0,0) ?

what is the equation for polygon external angles sum? For internal angles (n-2)180. (n is no.of sides).

In case of the traingles or polygons if they say as "measure of the sides" - does it mean length of the side or angle of the side?
JadranLee
ManhattanGMAT Staff
 
Posts: 108
Joined: Mon Aug 07, 2006 10:33 am
Location: Chicago, IL
 

by JadranLee Thu May 10, 2007 12:07 pm

Nice job, Saurabh. Here are a couple of links that illustrate Saurabh's point about angles in a polygon:

http://www.mathopenref.com/polygoninteriorangles.html

http://www.mathopenref.com/polygonexteriorangles.html
Saurabh Malpani
 
 

by Saurabh Malpani Thu May 10, 2007 9:41 pm

Thanks, Jad great material..I liked the sources...now I see how guys must be deonstrating things in class Impressive!!!

Saurabh malpani


JadranLee Wrote:Nice job, Saurabh. Here are a couple of links that illustrate Saurabh's point about angles in a polygon:

http://www.mathopenref.com/polygoninteriorangles.html

http://www.mathopenref.com/polygonexteriorangles.html