The rapid growth in diversity of information and communication technologies (ICT) enables a range of teaching methods, learning support strategies, and education settings to be developed. Questions about appropriate, effective, and efficient use of educational technology in teaching mathematics have been gaining more attention. This study focuses on the design and testing of an interactive learning textbook (eBook), created with GeoGebra applets and up-to-date web technologies. The eBook is designed to meet the pedagogical and didactic needs of learners, allowing a high degree of interactivity and feedback during the learning process. In order to determine the effect of the created materials on students' achievements, tests of knowledge as well as tests of retention of knowledge were used. Moreover, questionnaires and interviews for students were developed to assess the impact of interactive textbooks on the perceptions of learners concerning mathematics, interactive materials, and the learning process. Students who have used the interactive eBook show statistically significant increased knowledge and knowledge retention compared to students who have attended the standard classes. Students also emphasized that tasks with interactive applets and new kind of learning materials inspired them to learn more, both in school and at home.