Triangles

Triangles are fundamental geometric figures with three sides, three vertices, and three angles. They are classified based on side lengths as equilateral, isosceles, and scalene, and by angle measures as acute, right, and obtuse. The sum of the interior angles in a triangle is always 180 degrees. The properties and theorems related to triangles, such as Pythagoras' theorem and the triangle inequality theorem, are essential in solving various mathematical problems involving both basic and advanced concepts.