libglu1-mesa binary package in Ubuntu Focal amd64

 GLU offers simple interfaces for building mipmaps; checking for the
 presence of extensions in the OpenGL (or other libraries which follow
 the same conventions for advertising extensions); drawing
 piecewise-linear curves, NURBS, quadrics and other primitives
 (including, but not limited to, teapots); tesselating surfaces; setting
 up projection matrices and unprojecting screen coordinates to world
 coordinates.
 .
 On Linux, this library is also known as libGLU or libGLU.so.1.
 .
 This package provides the SGI implementation of GLU provided by the
 Mesa project (ergo the "-mesa" suffix).

Source package