Hi,

Each pair of lines intersects at a point which is a vertex of the triangle, hence you need to solve each pair of lines for the coordinates of the vertex. For example with lines 1 and 2 you have

4x+3y+1=0
4x-3y-17=0

I would add the two equations to get

8x - 16 = 0

so

x = 2.

Substitute x = 2 into equation 1 to find y = -3 and hence one vertex is (2, -3).

Find the intersection of lines 2 and 3 and then lines 1 and 3.

Harley