若坐标原点O到直线x/a+y/b=1 的距离为1

Because（x/a）+（y/b）=1 is in interpect form
So X-intercept (a,0) Y-intercept (b,0)

There is a right triangle which two sides are a and b and hypotenuse is (a^2+b^2)^(0.5)

So the area of this triangle is not only 0.5ab but also 0.5(1)(a^2+b^2)^(0.5)

0.5(1)(a^2+b^2)^(0.5)=0.5ab
a^2+b^2=a^2b^2

from the equation above, can get ab greater than 2