1) The study examines factors influencing geometry achievement across six countries using TIMSS 2011 data, focusing on opportunities to learn (OTL) as defined by curriculum content, instruction time, and teacher quality. 2) Results found OTL factors were differentially related to achievement depending on country, with geometry content coverage and teacher preparedness not predicting achievement in most cases. Instruction time was important for Japan but homework time showed mixed effects. 3) There are complex interplays between socioeconomic status, curriculum time allocation, and achievement that differ in each education system and require more detailed qualitative analysis.