New posts in triangles

Problem with the Pythagorean theorem [duplicate]

geometry triangles fake-proofs

Is a triangle with two equal angles always isosceles?

geometry trigonometry triangles

Isosceles triangle with duplicated side of 2 each and base $1+\sqrt{5}$, find the third angle.

geometry triangles

Show that a triangle is right angled

triangles circles

Circle and triangle

geometry euclidean-geometry triangles circles

Prove that the perpendiculars from P,Q,R to BC,CA,AB respectively are also concurrent.

analytic-geometry triangles

Sliver triangle

geometry triangles

Number of triangles $\Delta ABC$ with $\angle{ACB} = 30^o$ and $AC=9\sqrt{3}$ and $AB=9$?

geometry algebra-precalculus trigonometry triangles plane-geometry

How do you identify the base & perpendicular of a right angled triangle.

triangles

What is the geometric interpretation of the value of the secant and cosecant of an angle?

geometry trigonometry terminology circles triangles

Proving the area is irrational for triangle with integer vertices

vectors triangles inner-products 3d integers

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

geometry euclidean-geometry triangles angle

What is a right triangle with its sides on x and y axis called?

terminology triangles

Relation between incentre of a triangle and a circle touching its two sides and circumcircle

geometry euclidean-geometry triangles circles plane-geometry

If a,b,c are sides of a triangle, prove: $ \sqrt{a+b-c} + \sqrt{b+c-a} + \sqrt{c+a-b} \le \sqrt{a} + \sqrt{b} + \sqrt{c} $

inequality triangles radicals geometric-inequalities karamata-inequality

Integer Triangle Radicals conjecture

geometry number-theory recreational-mathematics triangles

Identity for $4\sin^2\alpha\sin^2\beta\sin^2\gamma$ expressed as product of terms $(\pm\sin\alpha\pm\sin\beta\pm\sin\gamma)$

trigonometry reference-request triangles

Sum of Angles in a Triangle.

geometry triangles

If, in a triangle, $\cos(A) + \cos(B) + 2\cos(C) = 2$ prove that the sides of the triangle are in AP

trigonometry triangles

Geometry problem with triangle

geometry triangles