OBM 1997 Problem 4

Let $V_n=\sqrt{F_n^2+F_{n+2}^2}$ , where $F_n$ is the Fibonacci sequence ( $F_1=F_2=1,F_{n+2}=F_{n+1}+F_{n}$ )

Show that $V_n,V_{n+1},V_{n+2}$ are the sides of a triangle with area $1/2$