# Material Detail

## Thales' Circle

Thales' Theorem: A triangle inscribed in a semicircle is right.

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##### Marcela Alcorn(Student)
18 years ago
This was probably by far my most favorite site of all. After browsing around
Thales' Circle and others for half an hour, I never became disinterested. Just
looking at all the illustrations and entering the applets of all types of math,
its shapes, forms and games, this was the best way for me to learn. This site is
a great teaching tool for any age, especially for those of us who are visual
and need to see it happen. I am very pleased with the site in general and with
the contents it holds,
EVERYTHING! Everything from arithmatic, geometry, complex numbers and more.
Apart of the fact that it was fun and educational it is extremely easy to use.
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##### galvan(Student)
18 years ago
It gives a good representation of theorum form.It shows specific examples on how
to apply to applications. It has great illustrations on material on learning
theorum forms.

Technical Remarks:

great teaching tool
Used in course? Yes
##### Tasha Stone(Student)
19 years ago
I enjoyed this site very much. Maybe if my 7th grade geometry teacher had used
this tool when teaching us, I might have understood. I am a visual hands on
person, I learn best that way. I spent about 15 minutes playing with all the
various applets on this website - thales circle, pythagorean theorem. Shows
formulas, types of triangles,
circles, lots of graphics. Whole program was very easy to use and educational
but need more instructional information. Site seems to assume that you already
have the basics of geometry down, which is why I think it would be great used in
conjunction with geomtery class. Site also reviews trigonometry and complex
numbers.

Technical Remarks:

No technical problems.
##### christine dominguez(Student)
20 years ago
I SPENT A 20 MINTUES PLAYIN WITH ALL THE ANNIMATIONS. THALES CIRLCE I JUST
FOOLED AROUND WITH THE ANIMATION TRYING TO ADJUST THE SEMICIRCLES IN DIFFERANT
ANGLES. THEN I LOOKED THROUGH DIFFERANT APPLETS. THE MATERIAL IS COOL BASICALLY
BECAUSE YOU CAN PLAY WITH THE ANIMATIONS AND SEE HOW THE DIFFERANT
ANGLES,TRIANGLE CIRCLES ECT.... WORK. I THINK THERE SHOULD BE MORE INSTRUCTION
TO IT AND LITTLE EXPLANATION BECAUSE I JUST MOVED THE MOUSE THE AROUND REALLY
NOT KNOWING WHAT I WAS SUPPOSED TO BE DOING. I THINK IS THIS IS TAUGHT TO
STUDENTS BY THE TEACHER THE STUDENTS CAN BE GREATLY ENHANCED. THE STRUDENT CAN
GET A BETTER UNDERSTANDING AND IT WILL MAKE IT EASIER FOR THEM TO UNDERSTAND THE
ANIMATIONS BETTER. AS A FIRST TIME USER I THINK ITS VERY COOL TO USE THE MOUSE
TO PLAY WITH ANIMATIONS, BUT YOU HAVE LOOK AT THE SITE KNOWING SOME KNOWLEDGE
##### Teacher Education Editorial Board(Faculty)
20 years ago
I spent approximately 1 hour reviewing the material at this site. I used one of the applets (Thales Circle) for mathematics methods classes.

Quality of Content

Excellent! I first saw this when I was searching for information on Thales Circle (James Stigler, The Learning Gap, mentions an eighth grade teaching/learning episode on Thales Circle.).

Potential Effectiveness

These animations provide a semi-concrete experience for students. If students just watch the animations, the students will not be helped much toward understanding the concept/principle being presented. If students take the next step and do the exercises themselves, those students' own understanding should be greatly facilitated. Also, this site would be good for expanding teachers' ideas of how to present the lessons to their own students.

If lesson plans accompanied these applets, this site would be great for teachers to use.

"This item is currently under review by the Teacher Education Editorial Board." 7

Technical Remarks:

Ease of Use

First time user would have to know about dragging and how to use interactive learning objects.

Requires level-4 (or higher) Java-enabled browser.

Delay: http://home.a-city.de/walter.fendt/me/anglesum.htm
The coloring (red) is very slow to cover the marked angle. This could interfere with students' understanding at first.