Recent advances in Multimodal Large Language Models (MLLMs) have achieved remarkable progress in general domains and demonstrated promise in multimodal mathematical reasoning. However, applying MLLMs to geometry problem solving (GPS) remains challenging due to lack of accurate step-by-step solution data and severe hallucinations during reasoning. In this paper, we propose GeoGen, a pipeline that can automatically generates step-wise reasoning paths for geometry diagrams. By leveraging the precise symbolic reasoning, GeoGen produces large-scale, high-quality question-answer pairs. To further enhance the logical reasoning ability of MLLMs, we train GeoLogic, a Large Language Model (LLM) using synthetic data generated by GeoGen. Serving as a bridge between natural language and symbolic systems, GeoLogic enables symbolic tools to help verifying MLLM outputs, making the reasoning process more rigorous and alleviating hallucinations. Experimental results show that our approach consistently improves the performance of MLLMs, achieving remarkable results on benchmarks for geometric reasoning tasks. This improvement stems from our integration of the strengths of LLMs and symbolic systems, which enables a more reliable and interpretable approach for the GPS task. Codes are available at https://github.com/ycpNotFound/GeoGen.

Multimodal mathematical reasoning has gained increasing attention in recent times. However, previous effective methods have not tried to reason in the form of natural language. In this paper, we introduce a model named MATHS (MultimodAl Transformer-based Human-readable Solver) for visual arithmetic and geometry problems in multimodal mathematical reasoning tasks. Drawing inspiration from Multimodal Large Language Models (MLLMs), our approach involves generating problem-solving processes expressed in natural language, in order to leverage the inherent reasoning capabilities embedded within language models. To address the challenge of precise calculations for language models, our work proposes a Math-Constrained Generation (MCG) method to impose hard constraints on generated outputs. Extensive experiments demonstrate our model excels in visual arithmetic task, and achieves results that are either better or comparable to existing methods in geometry problems. Code is available at https://github.com/ycpNotFound/MATHS.