ABSTRACT
Covid-19 is having an impact on education around the world. The Government and the Indonesian Education Office issued regulations regarding education in this pandemic era. This study aims to describe the syntax and semantics of mathematics students in the pandemic-era Trigonometry material. This research uses a qualitative approach and type of case study research. The research subjects were taken as many as six people based on their level of mathematical ability: high, medium, and low. Data collection techniques used are test or exam techniques and interviews. Based on the results of research and discussion, the number one reasoning used by the subjects tends to be both semantic and syntactic. All subjects use the properties of rectangles and the Pythagorean theorem for right triangles. However, in question number 2, subjects with high abilities use both reasoning, and subjects with moderate and low skills tend to use syntactic reasoning. It can be seen from the answers that only use the formula but do not know its usefulness in solving the problem.
