It doesn't waste time. It presents the problem, lets you struggle, and (in most versions) provides rigorous solutions that teach you how to write proofs. Community Standard:
Many university math departments (e.g., University of Chicago, Stanford) host PDFs of contest problems for training teams. Search your target university's "Math Olympiad Training" page. 107 geometry problems pdf
Downloading the PDF is not enough. You need a strategy. Here is a 4-week plan used by AIME qualifiers: It doesn't waste time
"Let $ABCD$ be a cyclic quadrilateral. Diagonals $AC$ and $BD$ intersect at $E$. Prove that $\frac{AE}{EC} = \frac{AB \cdot AD}{CB \cdot CD}$." Here is a 4-week plan used by AIME
The "107 geometry problems pdf" covers a range of topics, including:
To convince you of the value of this resource, let’s walk through the types of "aha!" moments that the forces upon you.