My question has been previously asked here (R How to multiply the values of the raster pixels with the true surfaces of these pixels?), I have to multiply the precipitation value of each cell by the area corresponding to each of these pixels under R. Except that I am working with the EPSG: 102024, Africa-Lambert-Conformal-Conic Coordinate system. Is it then an unprojected raster? In ther words, do I also have to use the function raster(r)? If not, how can I get the area corresponding to each of these pixels of my raster in R?