# Triangles

Geometry Level pending

Triangle is formed by the lines $$x+y=0$$, $$x-y=0$$ and $$lx+my=1$$. If $$m$$ and $$l$$ vary subject to the condition $$l^2+m^2=1$$ and the circumcentre of the triangle is $$(h,k)$$, then find the value of $$\dfrac{(h^2-k^2)^2}{h^2 + k^2}$$.

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