Due to the difficulty of the original text, many students use "bridge" books before tackling Federer directly. If you find the PDF too dense, consider these resources:
Most university libraries provide free PDF downloads of Springer titles via SpringerLink for students and faculty. federer geometric measure theory pdf
To help you get started with the right materials, I can provide more specific guidance if you tell me: Are you a or an undergraduate ? Due to the difficulty of the original text,
I can then recommend the specific chapters or supplementary notes that will be most helpful for your level! federer geometric measure theory pdf