Problem 39 Show that the triangle whose angles satisfy the equality sin2(A)+sin2(B)+sin2(C)cos2(A)+cos2(B)+cos2(C)=2\frac{sin^2(A) + sin^2(B) + sin^2(C)}{cos^2(A) + cos^2(B) + cos^2(C)} = 2cos2(A)+cos2(B)+cos2(C)sin2(A)+sin2(B)+sin2(C)=2 is a rectangular triangle.