# The Contact Triangle and Two Other Subtriangles

The Contact Triangle and Two Other Subtriangles

Let ABC be a triangle. Let A', B', and C' be the vertices of the contact triangle (the triangle with vertices where the incircle touches the sides of ABC). If , , and , then .

x=area(A'B'C')

y=area(AC'A')

z=area(CC'A')

x(y+z)=2yz