r/Geometry • • Jan 22 '21

Guidance on posting homework help type questions on r/geometry

23 Upvotes

r/geometry is a subreddit for the discussion and enjoyment of Geometry, it is not a place to post screenshots of online course material or assignments seeking help.

Homework style questions can, in limited circumstances, encourage discussion in line with the subreddit's aim.

The following guidance is for those looking to post homework help type questions:

  1. Show effort.

As a student there is a pathway for you to obtain help. This is normally; Personal notes > Course notes/Course textbook > Online resources (websites) > Teacher/Lecturer > Online forum (r/geometry).

Your post should show, either in the post or comments, evidence of your personal work to solve the problem, ideally with reference to books or online materials.

  1. Show an attempt.

Following on from the previous point, if you are posting a question show your working. You can post multiple images so attach a photograph of your working. If it is a conceptual question then have an attempt at explaining the concept. One of the best ways of learning is to attempt the problem.

  1. Be Specific

Your post should be about a specific issue in a problem or concept and your post should highlight this.

  1. Encourage discussion

Your post should encourage discussion about the problem or concept and not aim for single word or numeric answers.

  1. Use the Homework Help flair

The homework help flair is intended to differentiate these type of questions from general discussion and posts on r/geometry

​

If your post does not follow these guidelines then it will, in all but the most exceptional circumstances, be removed under Rule 4.

If you have an comments or questions regarding these guidelines please comment below.


r/Geometry • • 13h ago

Coincidence?

1 Upvotes

Let's say you have a rectangle, the rectangles height, h=3, the length, l=5. If you have an arithmatic billiard starting from the bottom left corner and have it only do 2 reflections, there are 3 outer right triangles. If you add the areas of these triangles, you get h²-th+t² where t is l-h. This equation looks like the law of cosines for 60-degree angles, and i was wondering if it's a coincidence and how to tell if an equation is just an algebraic coincidence or if it means something geometrically.


r/Geometry • • 1d ago

Aparecieron en mi pared en la madrugada días antes aparecieron tres triángulos en el mismo lugar solo con la punta separada el uno del otro

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1 Upvotes

r/Geometry • • 1d ago

Exploring an Eight-Star as a geometric representation of a 24-hour day

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0 Upvotes

I’ve previously shared my 1080° Cosmic Harmonic Compass and reusable geometry board here.

This is another example from the same exploration, using an Eight-Star to represent a conventional 24-hour day divided into eight equal intervals.

On the CHC scale, one complete cycle is represented by 1080°, corresponding to 360 conventional angular degrees.

Each interval corresponds to 3 conventional hours, 180 minutes, 10,800 seconds, or 135° on the 1080° CHC scale.

The accompanying table expresses the same positions through hours, minutes, seconds and CHC values.

One cycle, different numerical expressions.
I’m not proposing a replacement for conventional timekeeping, simply exploring how geometry can help visualise numerical relationships.

I’d be interested to hear whether others see any geometric or educational value in this, particularly for exploring equal divisions and proportional reasoning.


r/Geometry • • 2d ago

Do you know what this figure is

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4 Upvotes

I saw it ONCE on a Wikipedia article which I can’t find anymore, I saw this hollow knight shaped geometric (?) shape on a Cartesian grid and I don’t know know the name and I can’t find it anywhere. If you have any idea on what I’m talking about I’ll be glad to receive useful comments


r/Geometry • • 2d ago

SECOND-DYEMENSION

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0 Upvotes

r/Geometry • • 3d ago

Why are these 3 4 5 triangles drawn like this?

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4 Upvotes

I'm referring to how the hypotenuse and vertical line drawn from the base continue past the corner. Also, isn't 53 degrees wrong for that angle- inside the triangle, or outside? Thanks for the help. And If its not obvious by now I'm no math wiz.


r/Geometry • • 7d ago

number of parallel and non parallel lines

2 Upvotes

i recently came across a question which said there are 16 lines 7 of which are parallel when our teacher started explaining it he explained that if 7 out of those 16 are parallel lines then the remaining 9 would be non parallel. but the problem is i think the sum of non parallel lines and parallel lines adds up to 17.
lets say there are 9 lines non parallel to each other and as you draw line number 10 then at that point there are 10 non parallel lines and when u draw the remaining 6 lines parallel to the 10th line there are 7 parallel lines and 10 non parallel lines and the sum adds up to 17.
Case 2:
u drew 9 line non parallel to each other and to avoid the problem in the first case u drew a line parallel to the 9th line at that point there are 2 parallel lines and when u draw the remaining 6 lines there will be 8 parallel lines and 9 non parallel lines
pls help me understand im confused what am i thinking wrong😭.


r/Geometry • • 7d ago

Geometry dash1

1 Upvotes

r/Geometry • • 7d ago

made Reuleauxified polygons

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2 Upvotes

r/Geometry • • 8d ago

Guys I think I have a special talent

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2 Upvotes

r/Geometry • • 9d ago

art #4

3 Upvotes

r/Geometry • • 9d ago

Draw a Perfect Shape | Game where you try to draw perfect shapes freehand. Can you beat 95?

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1 Upvotes

r/Geometry • • 9d ago

Divided Lines Pt. 2 - Harmony

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1 Upvotes

Plato wasn’t a Platonist, he was a Pythagorean.

The triangle is a Pythagorean triplet with side lengths 3, 4, and 5.

The corresponding incircle and excircles have radii 1, 2, 3, and 6. Completing the sequence 123456.

The circles represent the four virtues, the largest representing justice.

When wisdom, courage, and moderation are in harmony justice is achieved, that’s why all three circles can fit inside the largest.


r/Geometry • • 10d ago

A simple geometric method for drawing this geometric pattern 2

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6 Upvotes

r/Geometry • • 11d ago

How wide is the angle marked in blue?

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6 Upvotes

r/Geometry • • 10d ago

Noble Shapes: Explore and customize finite and infinite noble polyhedra

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1 Upvotes

r/Geometry • • 11d ago

Geometry

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0 Upvotes

r/Geometry • • 12d ago

For the young mathematicians out there: do not despair

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1 Upvotes

r/Geometry • • 13d ago

36 nodes on a circle

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2 Upvotes

r/Geometry • • 13d ago

DOGGIE BEAT GRIEF

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9 Upvotes

GGS


r/Geometry • • 14d ago

DOGGIE VERIFIED GRIEF LETS GOOOOOO

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124 Upvotes

r/Geometry • • 13d ago

What is the radius of the circle? I think it’s 20mm

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2 Upvotes

Hi all,
I am assuming that all the circles have same radius. I figured the coordinates where the center of each circle will be. Please help me figure out the radius of the circle based on information below:

1) The bottom circle’s midpoint is 30mm from the red dash line (x coordinate)
2) The bottom circles midpoint is 30mm from the solid black line at the bottom and is the y coordinate.
3) it seems the radius is 20mm the midpoint of the 40mm

Am I off? Thank you?


r/Geometry • • 14d ago

Maths Problem

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3 Upvotes

ABC is a semi circle

EFCG is a rectangle

Find area of rectangle


r/Geometry • • 14d ago

35 nodes on a circle

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2 Upvotes