Questions tagged [geometry]
For questions related to geometric shapes, congruences, similarities, transformations, as well as the properties of classes of figures, points, lines, angles.
211 questions
13 votes
4 answers
4k views
How practically useful is the Law of Sines?
Does anyone have any good practical applications or theoretical extensions for the Law of Sines? I always struggle when trying to present this topic to students because it seems to just come out of ...
- 539
1 vote
0 answers
73 views
Illustrations showning Desargues's theorem and its concrete realization in perspective drawing equally clearly?
On the web one can find many images explaining perspective drawing in practical terms. One can also find many images illustrating Desargues's theorem, stating that two triangles are centrally ...
- 2,278
5 votes
4 answers
211 views
Applications of concurrence of lines associated with a triangle
The three angle bisectors of any triangle are concurrent. The three perpendicular bisectors of any triangle are concurrent. The three medians of any triangle are concurrent. The three altitudes of any ...
- 2,278
4 votes
1 answer
230 views
Concrete geometrically appealing example of a bijection between a circle and a line
The Cantor–Bernstein theorem says that if there is a one-to-one function from a (typically infinite) set $A$ into a set $B$ and another one-to-one function form $B$ into $A,$ then there is some ...
- 2,278
5 votes
4 answers
2k views
For graphics programming, is it better to start with an applied math book or dive into a deeper book like Linear Algebra Done Right?
I'm a self-taught learner getting into graphics programming, and I've started learning some applied math related to it. But at some point, I felt like I was just using formulas without really ...
- 51
4 votes
3 answers
208 views
How to create a lesson for students developing definitions in geometry
I'm a student in California getting my teaching certification. I have to create a lesson plan based on Geometry standard G-CO.4. Unfortunately picking a new standard is not an option, and I should ...
- 143
-3 votes
2 answers
167 views
Visualizing Pythagorean Theorem & Area Formulas for Elementary Students [closed]
Pythagorean Theorem Visual Proof for Elementary Students Hello, I have a question for all the teachers and experts here. I’m an elementary school teacher, and I’ve created a visual aid and proof ...
- 95
14 votes
7 answers
4k views
Why divide by three while calculating the volume of a cone or a pyramid?
As all of us know (at least I hope), we can easily see that the volume of a cone (or of a pyramid) can be calculated by the formula $V=\frac{G \times h}{3}$, where $G$ is the surface of the ground ...
- 3,275
3 votes
5 answers
467 views
What are some Geometry books with problems harder than McDougal Littell's "Geometry"?
I am currently studying in Honors Geometry. Our textbook is Geometry by McDougal Littell. The reason I am looking for harder problems is because I always feel like the test problems are harder than ...
4 votes
3 answers
494 views
The addition postulate can be proven? [closed]
In the very beginning of a geometry book, the Ruler Postulate is introduced: Every point on a line can be paired with a unique real number. (exact quotes) Then, the Segment Addition Postulate is ...
- 143
0 votes
4 answers
961 views
How to teach Shapes?
I am planning to teach kids and do it properly so was going through Chapter 2 of 1st Grade Maths Text Book from NCERT India (here) so this is about shapes and before I REALLY Read it, I started ...
- 419
4 votes
3 answers
1k views
How does one call two triangles that are image by a rotation one each other?
Identical (i.e. isometric) triangles are the image of each other one by any isometry or composition of isometries. But is there a name for two triangles that are the image from one another by a ...
- 437
4 votes
7 answers
3k views
How to teach high school students to analyze diagrams in a proof?
I work as a math intervention teacher with high school sophomores who are currently taking geometry. The sequence of instruction is as followed (so far this year): Introduction to geometry - naming ...
- 41
1 vote
1 answer
183 views
Should I let go of some of the things I planned to learn, or should I take it as a challenge to try to accomplish all of the things I planned to do?
I'm a new graduate student majoring in pure mathematics, I prefer topics about geometry and algbra. I have spent three months in this grad school and I found the fact is despressing. There are several ...
10 votes
6 answers
5k views
What is the simplest formula for calculating the circumference of a circle?
I am studying for a test to become a "paraeducator/instructional aid." One of the pages in the study guide has this information on computing area and perimeter and circumference and such: ...
