“🔺” meaning: red triangle pointed up Emoji

A triangle is a polygon with three edges and three vertices. It is one of the basic shapes in geometry. A triangle with vertices A, B, and C is denoted △ A B C {\displaystyle \triangle ABC} .In Euclidean geometry, any three points, when non-collinear, determine a unique triangle and simultaneously, a unique plane (i.e. a two-dimensional Euclidean space). In other words, there is only one plane that contains that triangle, and every triangle is contained in some plane. If the entire geometry is only the Euclidean plane, there is only one plane and all triangles are contained in it; however, in higher-dimensional Euclidean spaces, this is no longer true. This article is about triangles in Euclidean geometry, and in particular, the Euclidean plane, except where otherwise noted. 🔗 Triangle
🌐: مثلث, Üçbucaq, Триъгълник, ত্রিভুজ, Trougao, Trojúhelník, Trekant, Dreieck, Τρίγωνο, Triángulo, Kolmnurk, مثلث, Kolmio, Triangle, משולש, त्रिभुज, Trokut, Háromszög, Segitiga, Triangolo, 三角形, სამკუთხედი, Үшбұрыш, 삼각형, Trikampis, Trijstūris, Segi tiga, တြိဂံ, Driehoek (meetkunde), Trekant, Trójkąt, Triângulo, Triunghi, Треугольник, Trojuholník, Trikotnik, Trekëndëshi, Троугао, Triangel, รูปสามเหลี่ยม, Üçgen, Трикутник, Tam giác, 三角形.