Geometry

Poly - multiples

Gons - sides, measurements

Images with multiple sides, measurements

Each image is a closed figure - there are no open sides

Regular - have "symnetrical" (same measure) sides and angles

Irregular - have different sides and angles of different measure

Polygon Names based on number of sideas and/or angles

Most common polygons of 3 sides are called

Triangles 

Triangles are named based on

length of Sides

measure of Angles

Triangle Names based on sides:

Scalene - unequal sides of triangle

Isosceles - 2 sides of triangle are equal

Equilateral - Equi = equal; Lateral - sides therefore they are triangles with equal meaure of 3 sides

Right angled triangle - one angle is of 90 deg

Acute Angled triangle - less than 90 deg

Obtuse Angled triangle - one angle is > 90deg