DDSA Solutions

Geometry

9 problems · 6 with full explanations

0 Easy4 Medium1 Hard
Geometry problems involve coordinates, lines, circles, and polygons. Key tools: cross product (orientation, area), dot product (angle), Graham scan (convex hull), and line intersection. Use long arithmetic to avoid floating-point errors when possible.

How to practice

To practice Geometry problems effectively, start with the Easy problems listed below, trace through each solution on paper, then re-implement without looking. When you can recognise the geometry pattern within 30 seconds of reading a new problem, move on to Medium difficulty. Use the related topic pages and our study guide for a structured progression.

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All Geometry problems