Learning material about plane slices in geometric shapes has prerequisite material for the affinity axis. An understanding of the affinity axis can be done with the help of magic straws. The purpose of this study is to provide alternative media to provide an understanding of the affinity axis for students who are constrained by limited computer equipment or computer equipment that is not qualified to install application programs that support learning. This research is a qualitative research. The instruments of this study were observation sheets on the ability to understand the affinity axis and interview guidelines for using magic straws in understanding the affinity axis. Data analysis technique is using data analysis techniques Miles and Huberman. The use of magic straws affects students' abilities regarding the affinity axis, the abilities obtained are students understanding 1) the concept of points that are in a plane, 2) to get an affinity axis, two points that are in a plane that can be connected, 3) a point can be connected with a point of yield an extension of the rib that is still in line with that point, the 4 affinity axes are not only on the base plane, but can also be on the top plane. There are several things that need to be considered, namely 1) selecting straight/not curved pipes when making cubes, 2) using cable ties to mark dots on the ribs so they don't interfere with the student's point of view, 3) when pulling two dots use mattress thread tightly/not loosely, 4) when you have obtained a plane section in the geometric shape, shade the section by connecting it using a mattress thread to the inside of the plane.