How Tall Is That?

How Tall Is That?

Topic Cluster

Pythagorean Theorem


Fei Liang 
Teacher of Mathematics 
Verakin High School of Chongqing
Chongqing, China 

梁菲 数学老师,中国重庆第二外国语学校

Lesson Feedback


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).




Instructor Biography

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.


Additional Online Resources

Wikipedia: Pythagorean theorem
This resource is a Wikipedia article on the Pythagorean Theorem.

Wikipedia: Trigonometric functions
This site is a Wikipedia article on trigonometric functions.

Using Similar Triangles to Make Indirect Measurement
This page, sponsored by SOPHIA, provides several resources related to using similar triangles to make indirect measurements.

National Council of Teachers of Mathematics: the Math Forum
This site, sponsored by Connecting Geometry, features the method of indirect measurement known as “Shadow Reckoning”.

Math is Fun: Introduction to Trigonometry
This site is sponsored by Math Is Fun and provides an introduction to trigonometry.

Universal Class: Introduction to Trigonometric Functions
This site provides an introduction to trigonometric functions and is sponsored by Universal Class

BLOSSOMS Video: How to Make a Protractor
Watch optional video: How to Make a Protractor (Mandarin, Flash)