Changes to the curriculum in Indonesia have also caused changes in the learning process. Students are required to play an active role in classroom learning, while teachers only act as facilitators. So that in this curriculum, students are expected to have self-regulated learning. But also, another aspect that must still be had by students is a good understanding of concepts, especially in a material that is considered difficult like mathematics. One alternative way that can be done to achieve both aspects is the use of instructional media, such as interactive multimedia. One interactive multimedia that can be used is the Macromedia Flash Professional 8 application. This study aims to compare two groups with different treatments on trigonometry material. This study uses a quasi-experimental method with the non-equivalent control group design. This study was divided into two groups; the first group was given learning using flash media as an experimental group and the second group as a control group using ordinary learning. The sample in this study was taken from two classes of thirteen classes with purposive sampling, namely class X RPL 2 and X AKKUL 1 in SMK Negeri 1 Cianjur. Data were analyzed using the Mann Whitney Test and the Independent Sample t/t′-test. The results showed that the achievements and increased ability to understand mathematical concepts from the experimental group were significantly better than the control group. Based on N-gain criteria, the increased is including the medium category. At the same time, the self-regulated learning of the experimental group is the same as the self-regulated learning of the control group.