Triangle
A triangle is a three-sided (and three-angled) polygon.
Triangle is an elementary-school-level concept.
It is listed in the California State Standards for kindergarten.
Examples
| Equilateral Triangle: |
A triangle in which all three sides are of equal length. In such a triangle, the angles are all equal as well. |
| Isosceles Triangle: |
An isosceles triangle is a triangle having (at least) two sides of equal length, and therefore also with (at least) two equal angles. |
| Right Triangle: |
A right triangle is a triangle that has a right angle. The Pythagorean Theorem is a relationship among the sides of a right triangle. |
Prerequisites
| Polygon: |
A polygon is a two-dimensional figure that consists of a collection of line segments, joined at their ends. |
Classroom Articles on Polygons
Classroom Articles on Geometry (Up to Elementary-School Level)
