This research aims to: 1) Produce valid mathematics learning media on the material of flat sides shapes assisted by pop ups book in SMP Negeri 1 Kembaran. 2) Knowing the teachers responses to the developed media. 3) Knowing the students responses to the developed media. This research uses a 4D development model: define, design, develop and desseminate which is modified into 3 stages, derine, design and development. The trial was carried out in SMP Negeri 1 Kembaran with 10 students of class VIII E as the research subject. From the research, it was found that the media developed had met the valid criteria by getting an average score of 4.57 from the lecturer validator and 4.21 from the teacher validator, the results of the teacher's response got an average score of 4.76 which indicated the pop up book media. helping the teacher deliver the learning material, the results of the student response get a percentage of 76% which shows pop-up books help students receive learning.