This page contains an index of all videos, broken down by subject area.

**Geometry**

- Video #201, Geometry vocabulary. This video covers the definitions of the following concepts: right angle, acute angle, obtuse angle, straight angles, adjacent angles, complementary angles, supplementary angles, vertical angles.
- Video #202: Triangle Vocabulary. This video covers the definitions of the following terms: Polygon; Triangle; Equilateral triangle; Isosceles triangle; Scalene Triangle; Acute Triangle; Right Triangle; Obtuse Triangle
- Video #203: Triangle Theorems. This video covers the following topics: Triangle angle sum theorem: The sum of a triangle’s angles equals 180 degrees; and Triangle inequality theorem: In any triangle, the sum of any two sides must be greater than the other side.

**For Parents**