Oai Thanh Đào's user avatar
Oai Thanh Đào's user avatar
Oai Thanh Đào's user avatar
Oai Thanh Đào
  • Member for 8 years, 8 months
  • Last seen more than 6 years ago
  • Việt Nam
15 votes
1 answer
708 views

A cubic and six conics problem

14 votes
1 answer
2k views

Dao's theorem on six circumcenters associated with a cyclic hexagon

13 votes
1 answer
602 views

Find structure geometry of $A_1, A_2,...,A_n$ such that $\prod_{i<j} A_iA_j$ is maximum

9 votes
1 answer
998 views

A chain of six circles associated with a conic

8 votes
1 answer
834 views

Three homothetic centers are collinear

7 votes
2 answers
1k views

A conjecture generalization of Karamata inequality

6 votes
1 answer
709 views

Continuing generalization of the Simson line

6 votes
0 answers
222 views

An inequality in cyclic polygon and tangential polygon

6 votes
1 answer
789 views

Relation of some Euclidean geometry theorems and more conjecture generalizations

5 votes
1 answer
427 views

Sixteen points circle - A conjecture on Möbius plane

5 votes
1 answer
360 views

A conjecture associated with n-gon cut curve of degree m

5 votes
1 answer
451 views

A generalization of Erdős–Mordell inequality [closed]

4 votes
1 answer
568 views

A conjecture like Cayley–Bacharach theorem

4 votes
1 answer
223 views

A conjecture for a curve cuts a curve - variant Cayley-Bacharach's theorem

4 votes
1 answer
675 views

A problem of four curves

4 votes
1 answer
1k views

A new theorem in projective geometry

3 votes
0 answers
229 views

A conjecture on six planes [closed]

2 votes
0 answers
266 views

A chain of six circles associated with six points on a circle (in Mobius plane) [closed]

2 votes
1 answer
238 views

A generalization of the Tucker circle theorem and the Thomsen theorem associated with a conic

2 votes
1 answer
487 views

Conjectute: no exist an equilateral triangle such that all vertices are integer numbers [closed]

2 votes
1 answer
695 views

Weighted version of the Karamata Inequality

2 votes
1 answer
133 views

Exist $A_1, A_2,\cdots , A_n$ be $n$ points on a sphere, satisfy if $i-j=l-m$ then $A_iA_j=A_lA_m$

2 votes
1 answer
173 views

An inequality on cyclic polygon defined by Newton's identities

2 votes
1 answer
725 views

Inspired from British Flag theorem

1 vote
1 answer
466 views

Inspire from Kantorovich Inequality

0 votes
1 answer
171 views

An inequality in product space $V$ [closed]

0 votes
1 answer
226 views

An inequality of real continuous function with f'>0 and f''>0