Abstrak Ujian Nasional memunculkan soal HOTS. Peserta didik di SMAN Rambipuji mengalami kesulitan menyelesaikan soal HOTS terutama materi aturan sinus dan cosinus, karena kurangnya pembelajaran berbasis HOTS di sekolah. Oleh karena itu, penelitian ini bertujuan untuk 1) mendeskripsikan perencanaan 2) mendeskripsikan proses pelaksanaan, dan 3) mendeskripsikan evaluasi pembelajaran berbasis HOTS materi aturan sinus dan cosinus kelas X di SMA Negeri Rambipuji. Penelitian menggunakan pendekatan kualitatif metode deskriptif. Pengumpulan data dilakukan dengan observasi pelaksanaan pembelajaran, wawancara guru dan siswa, dan dokumentasi RPP HOTS. Data dianalisis menggunakan teori Miles dan Huberman, yaitu pengumpulan data, kondensasi data, menyajikan data, dan penarikan kesimpulan. Teknik keabsahan data menggunakan triangulasi sumber dan triangulasi teknik. Hasil penelitian menunjukkan bahwa kegiatan implementasi pembelajaran berbasis HOTS adalah 1) Perencanaan dilaksanakan dengan membuat silabus dan RPP. Dalam RPP terdapat tujuan pembelajaran dan kegiatan inti yang terkandung indikator dari kegiatan berpikir tingkat tinggi meskipun masih ada yang di bawah level C3. 2) Pelaksanaan pembelajaran dilakukan menggunakan aktivitas berpikir tingkat tinggi meskipun belum semua aktivitas terlaksana. 3) Evaluasi pembelajaran dilakukan saat PAS genap. Guru tidak menggunakan soal HOTS untuk materi aturan sinus dan cosinus, tetapi ada soal berbasis HOTS yang digunakan di luar materi tersebut. Guru belum menerapkan kegiatan evaluasi berbasis HOTS sepenuhnya.   Abstract The National Examination raises HOTS questions. Students at SMAN Rambi Puji have difficulty solving HOTS questions, especially the sine and cosine rules, because of the lack of HOTS-based learning at school. Therefore, this study aims to 1) describe the planning 2) describe the implementation process, and 3) describe the evaluation of HOTS-based learning on the sine and cosine rules of class X at Rambi Puji High School. The research used a qualitative descriptive method approach. Data was collected by observing the implementation of learning, teacher and student interviews, and documentation of the HOTS lesson plans. The data were analyzed using the theory of Miles and Huberman, namely data collection, data condensation, presenting data, and drawing conclusions. The data validity technique uses source triangulation and technical triangulation. The results of the study indicate that the implementation of HOTS-based learning activities are 1) Planning is carried out by making syllabus and lesson plans. In the lesson plans there are learning objectives and core activities that contain indicators of higher-order thinking activities, although some are still below the C3 level. 2) The implementation of learning is carried out using higher-order thinking activities even though not all activities have been carried out. 3) Learning evaluation is carried out when PAS is even. The teacher does not use HOTS questions for the sine and cosine rule material, but there are HOTS-based questions that are used outside the material. Teachers have not fully implemented HOTS-based evaluation activities.