Questions tagged [geometry]
For questions about geometric shapes, congruences, similarities, transformations, as well as the properties of classes of figures, points, lines, and angles.
52,610 questions
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Identify the flaw in my proof [closed]
they said I had to find AE,the actual answer is 64/11 but I have the answer at 6,my math teachers said i was correct since they could nt find any errors with my proof
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similar to a classical geometry result
Let $\triangle ABC$ be a triangle and $O$ its circumcenter.
We define $f(\triangle ABC) = \triangle A'B'C'$ such that $A',B',C'$ are the circumcenters of the triangles $\triangle OBC,\triangle OCA, \...
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What about the percepti relationship between the circumference of a circle and the circumference of its inner square:? [closed]
The relationship between the circumference of a circle and the circumference of its inner square:
I drew a circle with a diameter d = 1 cm and a radius r = 0.5 cm. Therefore, the circumference of the ...
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Is there a good reason why regular n-gon geometry would appear in the zeroes of the Riemann zeta function?
Note: this post is the speculation of a non-mathematician who is learning by playing with unreasonably hard topics like a toy (i.e. meaninglessly, as you'll see)
As I understood, in some cases ...
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How to prove that $n=7$
On the line $d$ we consider the points
$A_1, A_2, \ldots, A_{15}$, all distinct two by two, such that
$
A_1A_2 = A_2A_3 = \cdots = A_{14}A_{15} = 1.$
Find the smallest natural number $n \ge 4$ with ...
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Is there something missing with this simple geometry problem?
I'm currently doing an exercise form my geometry book. The question is asking for the volume of the pyramid $N.ABCD$ (i.e. a pyramid of base $ABCD$ and with the tip $N$). The construction is as ...
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Semicircle with tangent and perpendicular: prove that DE·BC = CD·R [closed]
Problem
Given a semicircle with diameter AB = 2R and center O. Let C be a point on the
extension of AB beyond B. From C, draw a tangent CD to the semicircle, touching
it at point D. The perpendicular ...
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1
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Explain this seeming contradiction in Euclid Book 1 Proposition 16
This proposition has been concluded without the use of the parallel postulate, because the first time Euclid invokes the parallel postulate is in I.27. Thus, it should apply to all geometries ...
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Given an $n$-gon, by how much must we increase the length of each of $k$ chosen sides so that they form a $k$-gon?
The polygon inequality states that the sum of any $n-1$ sides of a $n$-gon greater than the $n$-th side.
Let $n \ge 4$ and $3 \le k < n$. Let a $n$-gon have positive side lengths $
a_1 \le a_2 \le \...
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if AB and AC are two tangents to a circle and ∠BAC = 116°, find the magnitudes of the angles in the two segments into which BC divides the circle. [closed]
I don't really understand what does the statement 'find the magnitudes of the angles in the two segments in which BC divides the circle' mean.'
Do I need to add a new tangent in order to create and ...
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Radium Rabbit Conjecture, version 3.0: The fractional part of the square of the area of a triangle with odd-integer sides is $\frac{3}{16}$. [closed]
Why Version 3.0?
In the earlier versions of this conjecture, I focused on triangles whose side lengths are distinct prime numbers.
Through the discussion that followed, it became clear that the ...
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Hot take on the "Coastline Paradox" [closed]
Edit:guys I don't mean to disrupt, I am really just an amateur and I would really appreciate if you let me know why I'm wrong or if I'm right
Note: this is just my view of the coastline paradox, if ...
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Can four points in a unit square have mutual distances all larger than 1?
Question: 4 points are given inside or on the boundary of a unit square. I have a conjecture that there must be 2 points at a distance $\leq 1$.
Progress: I’ve found that this question is a corollary ...
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Six circles in a rectangle: show that two lengths are equal
The diagram shows a rectangle, six circles, and a red line segment joining the centres of two circles. Wherever things look tangent, they are tangent. (The tangencies imply that there are three pairs ...
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Inscribed equilateral triangle side [closed]
In the picture there are two small circles with centers B and C, crossing at D, whose center lie on top of the large circumference.
I know that line AB is the side of an equilateral triangle, and that ...
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