finding unknown vertices of triangle from line equations  TOPIC_SOLVED

Geometric formulae, word problems, theorems and proofs, etc.

finding unknown vertices of triangle from line equations

Postby Motherof8 on Mon Jan 16, 2012 7:57 pm

The problem states: Lines y = 3 + 2/3x, y =-1/3x, and y = -4/3x +3 intersect to form a triangle. Find the verticies. I solved for x by substituting x for y, then I solved for y and started to plot the lines on a graph. I get a constant value for x, and different values for y, which doesn't form a triangle. Did I do the wrong thing?
Motherof8
 
Posts: 46
Joined: Sat Feb 12, 2011 12:32 am

Sponsor

Sponsor
 

Re: finding unknown vertices of triangle from line equations  TOPIC_SOLVED

Postby maggiemagnet on Mon Jan 16, 2012 11:39 pm

Motherof8 wrote:The problem states: Lines y = 3 + 2/3x, y =-1/3x, and y = -4/3x +3 intersect to form a triangle. Find the verticies. I solved for x by substituting x for y, then I solved for y and started to plot the lines on a graph. I get a constant value for x, and different values for y, which doesn't form a triangle. Did I do the wrong thing?

Without seeing what you got or how, it's hard to say. But you might want to start with the fact that the corners of the triangle are where pairs of lines cross. So pick a pair of lines and find the intersection for that pair. That's one corner. Then do a different pair. Then do the last pair. You should get three points. Each one is the "solution" to a "system" that you made up by pairing lines, and each is also a corner point of the triangle.
:clap:
User avatar
maggiemagnet
 
Posts: 294
Joined: Mon Dec 08, 2008 12:32 am


Return to Geometry

cron