diff --git a/guide/english/mathematics/triangle/index.md b/guide/english/mathematics/triangle/index.md index dea0b0865e..5bc9ba1a40 100644 --- a/guide/english/mathematics/triangle/index.md +++ b/guide/english/mathematics/triangle/index.md @@ -3,13 +3,28 @@ title: Triangle --- ## Triangle -This is a stub. Help our community expand it. +A triangle is a polygon which has three sides and vertices, whose internal angles add up to 180 degrees. -This quick style guide will help ensure your pull request gets accepted. +Any side of a triangle can be considered a base (B). - +The distance from the base to the vertice that does not touch it is the height (H). + +### Classifications + +- A right triangle is a triangle that contains one angle equal to 90 degrees. + +- An acute triangle is a triangle that consists entirely of angles less than 90 degrees. + +- An obtuse triangle is a triangle that contains one angle more than 90 degrees. + +- An equilateral triangle's 3 sides and angles are always equal in length and degree (and therefore the angles are equal to 60 degrees). + +- An isosceles triangle has 2 sides and angles that are equal in length and degree. + +- A scalene triangle has no sides or angles that are equal in length or degree. + +![triangle](https://upload.wikimedia.org/wikipedia/commons/e/eb/Regular_polygon_3_annotated.svg "triangle") #### More Information: - - +- [Wikipedia](https://en.wikipedia.org/wiki/Triangle)