Geometry & Trig Reference

Math formulas, definitions, properties, diagrams and examples from Geometry and Trigonometry 

Geometry Stuff
Perimeters Areas
Circle Stuff
The Geometry of Circles: 
Definitions and formulas for the radius of a circle, the diameter of a circle, the circumference (perimeter) of a circle, the area of a circle, the chord of a circle, arc and the arc length of a circle, sector and the area of the sector of a circle
The Trigonometry of Circles:
Definitions and formulas for the arc and the arc length of a circle, sector and the area of the sector of a circle, the unit circle, the angles on the unit circle in radians, the angles on the unit circle in degrees, the points on the circumference of the unit circle
Triangle Stuff
Notations:
Geometry notations for triangles including the right triangle, congruent sides of a triangle and congruent angles of a triangle
The Geometry of Triangles:
Definitions and formulas for the area of a triangle, the sum of the angles of a triangle, the Pythagorean theorem, Pythagorean triples and special triangles (the 30-60-90 triangle and the 45-45-90 triangle)
Types of Triangles:
Definitions and formulas for triangles including right triangles, equilateral triangles, isosceles triangles, scalene triangles, obtuse triangles and acute triangles
The Trigonometry of Triangles:
Definitions and formulas for basic trigonometry, sine, cosine, tangent, cosecant, secant, cotangent, the law of sines and the law of cosines
Quadrilateral Stuff:
Definitions and formulas for perimeter and area, properties of sides and angles, diagrams
Squares Rhombuses (Rhombi)
Rectangles Kites
Parallelograms Trapezoids
Properties of Polygons:
Information on properties, interior angles and central angles
Triangles Quadrilaterals          Pentagons
Hexagons Heptagons Octagons
Nonagons Decagons 11-gons
Dodecagons