What shape is the DNA in eukaryotic cells?

It depends on which state the cell is in. You can get a quick overview of the different 'shapes' it inhabits during cell division here. read more

Certain domains of the DNA also change shape (or structure) depending on whether it is ‘active’ (this is the short version, but you can read up on epigenetics, histone acetylation, DNA methylation etc. for more details), and whether it is being transcribed. read more

Though the eukaryotic cells have different shape, size and physiology but all the cells are typically composed of plasma membrane, cytoplasm and its organelles, viz., mitochondria, endoplasmic reticulum, ribosomes,-Golgi complex etc., and a true nucleus. read more