This video shows how to make a basic clinometer from classroom materials. The materials may include a protractor, a thin string, a drinking straw, a weight tied to the string (e.g., a key), and transparent tape. Subsequently, the teacher uses it to measure an object's height, such as a building, in real life. A clinometer can be used to find the angle you are looking, for instance, from where you are standing to the top of a building. Combined with the distance to the base of the building and some knowledge in trigonometry, this can be used to calculate the building’s height. The teacher also suggests that students can work in pairs (one observer and one recorder) and carry out a peer cooperative learning activity to observe and measure a specified object’s height directly.