Do Large Language Models Truly Understand Geometric Structures?
Xiaofeng Wang, Yiming Wang, Wenhong Zhu, Rui Wang
TL;DR
This work introduces GeomRel, a dedicated benchmark that isolates geometric Relationship Identification (GRI) to more accurately assess whether LLMs truly understand geometric structures, revealing substantial weaknesses in current models, especially for angle-based relations. To address these gaps, the authors propose GeoCoT, a two-stage Geometry Chain-of-Thought prompting approach that first breaks down geometry into fundamental elements and then applies reverse reasoning to infer relations, yielding notable improvements across basic and advanced datasets. Through broad evaluations across nine LLMs, various data-diversity operations, and prompting strategies, the paper demonstrates that end-to-end accuracy can obscure underlying deficits in geometric understanding and that explicit, structured reasoning substantially boosts performance. The findings suggest a practical direction for enhancing LLM geometric reasoning, with GeoCoT offering a scalable method to improve model reliability in geometry-related tasks.
Abstract
Geometric ability is a significant challenge for large language models (LLMs) due to the need for advanced spatial comprehension and abstract thinking. Existing datasets primarily evaluate LLMs on their final answers, but they cannot truly measure their true understanding of geometric structures, as LLMs can arrive at correct answers by coincidence. To fill this gap, we introduce the GeomRel dataset, designed to evaluate LLMs' understanding of geometric structures by isolating the core step of geometric relationship identification in problem-solving. Using this benchmark, we conduct thorough evaluations of diverse LLMs and identify key limitations in understanding geometric structures. We further propose the Geometry Chain-of-Thought (GeoCoT) method, which enhances LLMs' ability to identify geometric relationships, resulting in significant performance improvements.
