m- 1=n+ 1，m-2=n

Combine hyperbola and ellipse, and eliminate y to get x? =2mn/(m+n)，

Replace the ellipse and get y? = 1-[2n/(m+n)]=2/(m+n)

The height of the triangle is: h=√2/(m+n)

The length of the base of the triangle is 2√(m- 1).

Area: √ (m-1) [2/(m+n)] =1.