This definition can be generalized to any triangle and any angle: The side of the triangle that is opposite of is the side of the triangle that is not a side of . This more general definition is not used as commonly as the definition for right triangles.
{opposit... ...15){$\theta$} \rput[l](0,0){.} \rput[a](4,0){.} \rput[b](4,4){.} \end{pspicture}](http://images.planetmath.org:8080/cache/objects/8012/l2h/img4.png "\begin{pspicture}(0,-2)(8,4) \pspolygon(0,0)(4,4)(4,0) \rput[l](4.1,2.1){opposit... ...15){$\theta$} \rput[l](0,0){.} \rput[a](4,0){.} \rput[b](4,4){.} \end{pspicture}")
