New posts in euclidean-geometry

Given $\triangle ABC$ with $\angle C = 60^\circ$, show $a^2+b^2-ab=c^2$ without trigonometry

geometry euclidean-geometry triangles

A hard problem from regular $n$-gon

euclidean-geometry

Find the area of overlap of two triangles

geometry euclidean-geometry analytic-geometry computational-geometry

Incircle of polygon tangent to a point

geometry euclidean-geometry polygons

How does this proof of the regular dodecahedron's existence fail?

geometry euclidean-geometry fake-proofs polyhedra platonic-solids

Question about the encyclopedia of triangle centers

geometry euclidean-geometry triangles

How to construct a square equal to a given triangle.

euclidean-geometry geometric-construction

Straightedge-only construction of a perpendicular

geometry euclidean-geometry contest-math

What's the measure of the $\angle POB$ in the circle below?

geometry euclidean-geometry plane-geometry

Circle and triangle

geometry euclidean-geometry triangles circles

What's the power of point $P $ in relation to the center the circumference $O2$?

geometry euclidean-geometry plane-geometry

how to solve this question of parabola by only using euclidean geometry?

euclidean-geometry conic-sections

Have you seen this golden ratio construction before with three squares (or just two) and circle ?Geogebra gives PHI or 1.6180.. exactly

geometry trigonometry euclidean-geometry golden-ratio

Find a point $X$, in the plane of regular pentagon $ABCDE$, that minimizes $\frac{XA+XB}{XC+XD+XE}$.

geometry optimization euclidean-geometry maxima-minima geometric-inequalities

Question regarding basis vectors of root reference frame...

matrices geometry vectors euclidean-geometry rotations

what is the maximum number of acute angles

euclidean-geometry

Solid angle between vectors in n-dimensional space

linear-algebra geometry vector-spaces euclidean-geometry

What's the value of the area of the triangle $ABC$ below?

geometry euclidean-geometry plane-geometry geometric-construction geometric-transformation

Scaling and rotating a square so that it is inscribed in the original square

geometry euclidean-geometry rotations polygons art

Solve the angle $\angle{DCB}$ in triangle $\triangle{ABC}$ with $\angle{A}=84^{\circ}$

geometry euclidean-geometry triangles angle