Special isosceles triangles
Problem 138
Consider the isosceles triangle with base length, , and legs, .

By using the Pythagorean theorem it can be seen that the height of the triangle, , which is one less than the base length.
With and , we get , which is one more than the base length, and this is the second smallest isosceles triangle with the property that .
Find for the twelve smallest isosceles triangles for which and , are positive integers.