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

[yamini]

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]

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

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]

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]

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

Saurabh malpani

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