This lesson is a practical lesson about measuring the height of different objects in daily life. Through this lesson, we hope that students will learn how to use simple tools to measure the height of objects whose height cannot be measured directly. In addition, students should get more understanding about how to use mathematical models to solve the problems in our lives. As a prerequisite to this lesson, students need to have some familiarity with the Pythagorean theorem, trigonometric functions and similar triangles -- which are the theoretical basis for the lesson. It would be better to teach this video in two lessons. In the first lesson, the teacher raises the questions and asks students to prepare for the solutions. The teacher would also explain the working principles of a protractor and the steps to use it. In the second lesson, the students would do the actual measurements using the tools they have prepared and discuss their proposals and results with each other. After that class, the teacher could lead the students to improve their current proposals or even to come out with new ones.
Watch supporting video: How to Make a Protractor (Mandarin, Flash).
I like mathematics. I think that the thinking methods for mathematics are the same as for many principles in our life. Math comes from life and should also serve life.
This resource is a Wikipedia article on the Pythagorean Theorem.
This site is a Wikipedia article on trigonometric functions.
This page, sponsored by SOPHIA, provides several resources related to using similar triangles to make indirect measurements.
This site, sponsored by Connecting Geometry, features the method of indirect measurement known as “Shadow Reckoning”.
This site is sponsored by Math Is Fun and provides an introduction to trigonometry.
This site provides an introduction to trigonometric functions and is sponsored by Universal Class.
Watch optional video: How to Make a Protractor (Mandarin, Flash)