Many studies revealed that a lot of students were confuse about the concepts of area measurement of plane figures including area measurement of circles. The main reason is because the school practices make students focus on memorizing formulas instead of understanding concepts. Therefore, in this study, a set of learning activities were designed as an innovation in learning area measurement. Those activities involved two models namely grid paper and reshaping which are respectively as a tool and a strategy to support students’ learning. This study was conducted in three stages which are preliminary design research was used as the research approach to achieve the aim. Thirty-eight of 8^th graders in Indonesia were involved in this study. The results indicate that using realistic problems, grid paper could stimulate students’ reasoning and understanding of the concepts of area of circles and the way to measure it informally. Moreover, reshaping strategy which is grounded from the concept of area conservation supports students understanding on the way to measure the area of circles and how the formulas of the area of plane figures relate each other. Besides that, the whole activities gave important role on distinguishing the area and perimeter of circles.