3. In a triangular pyramid, two of the three sides are isosceles right triangles, and the other is an equilateral triangle with a side length of 1. Then, such a triangular pyramid has

保留源文本的换行和格式，直接输出翻译结果。 

Note: The last sentence "保留源文本的换行和格式，直接输出翻译结果。" is in Chinese and is not part of the translation. It is an instruction to ensure the format is maintained.
3.3.

Regarding the tetrahedron $ABCD$, there are the following 3 cases:
(1) $AB=AC=BC=AD=1, CD=BD=\sqrt{2}$;
(2) $BC=BD=CD=1, AB=AC=AD=\frac{\sqrt{2}}{2}$;
(3) $AB=BC=AC=AD=BD=1, CD=\sqrt{2}$.