New posts in triangles

Probability distribution for the perimeter and area of triangle with fixed circumscribed radius

probability probability-theory probability-distributions circles triangles

Prove that the area of $\triangle DEF$ is twice the area of $\triangle ABC$

geometry circles triangles

Calculate coordinates of 3rd point (vertex) of a scalene triangle if angles and sides are known.

trigonometry triangles triangulation

Proving that the sum of any two sides of the triangle is greater than the third side

geometry trigonometry inequality triangles

Maximum area of a rectangle inscribed in a triangle is $1/2$ the area of triangle

geometry euclidean-geometry triangles

Bisection of a a triangular area

geometry euclidean-geometry contest-math triangles area

The concurrence of angle bisector, median, and altitude in an acute triangle

euclidean-geometry triangles

Calculate the ratio based on the lengths of edges of triangle

geometry euclidean-geometry triangles circles

Smallest square containing a given triangle

euclidean-geometry triangles rectangles

Unit square inside triangle. [duplicate]

geometry euclidean-geometry triangles area geometric-inequalities

Series for envelope of triangle area bisectors

sequences-and-series geometry triangles area

Alternate proof for $a^2+b^2+c^2\le 9R^2$

geometry inequality triangles alternative-proof geometric-inequalities

How to prove that $\frac{r}{R}+1=\cos A+\cos B+\cos C$?

geometry trigonometry triangles

Can a non-equilateral triangle with integer sides and integer angles (in degrees) exist?

geometry trigonometry triangles

An angle inside a regular pentagon

geometry triangles

How to maximize the area of a triangle, given two sides?

geometry optimization triangles area maxima-minima

Let $P$ be a point inside $\triangle{ABC}$ such that $\angle{ABP}=10^\circ, \angle{BAP}=\angle{BCP} = 20^\circ$. Show $\triangle{ABC}$ is an isosceles

geometry euclidean-geometry triangles

Another beauty hidden in a simple triangle (2)

euclidean-geometry triangles

Distance between incentre and orthocentre.

geometry trigonometry euclidean-geometry triangles

Under what conditions will the rectangle of the Japanese theorem be a square?

geometry triangles rectangles