Dr. Formula

CIRCLE bukan bulat(^-^)

Area Of Circle->   or  
Area Of Sector->  
Area Of Segment-> 

*source: wikipedia




Polygon Formulas
(N = # of sides and S = length from center to a corner)
Area of a regular polygon = (1/2) N sin(360°/N) S²Sum of the interior angles of a polygon = (N - 2) x 180°
The number of diagonals in a polygon = 1/2 N(N-3)
The number of triangles (when you draw all the diagonals from one vertex) in a polygon = (N - 2)

Polygon Parts

Side - one of the line segments that make up the polygon. Vertex - point where two sides meet. Two or more of these points are called vertices. Diagonal - a line connecting two vertices that isn't a side. Interior Angle - Angle formed by two adjacent sides inside the polygon. Exterior Angle - Angle formed by two adjacent sides outside the polygon.

Special PolygonsSpecial Quadrilaterals - square, rhombus, parallelogram, rectangle, and the trapezoid. Special Triangles - right, equilateral, isosceles, scalene, acute, obtuse. Polygon Names Generally accepted names Sides Name n N-gon 3 Triangle 4 Quadrilateral 5 Pentagon 6 Hexagon 7 Heptagon 8 Octagon 10 Decagon 12 Dodecagon Names for other polygons have been proposed. Sides Name 9 Nonagon, Enneagon 11 Undecagon, Hendecagon 13 Tridecagon, Triskaidecagon 14 Tetradecagon, Tetrakaidecagon 15 Pentadecagon, Pentakaidecagon 16 Hexadecagon, Hexakaidecagon 17 Heptadecagon, Heptakaidecagon 18 Octadecagon, Octakaidecagon 19 Enneadecagon, Enneakaidecagon 20 Icosagon 30 Triacontagon 40 Tetracontagon 50 Pentacontagon 60 Hexacontagon 70 Heptacontagon 80 Octacontagon 90 Enneacontagon 100 Hectogon, Hecatontagon 1,000 Chiliagon 10,000 Myriagon To construct a name, combine the prefix+suffix Sides Prefix 20 Icosikai... 30 Triacontakai... 40 Tetracontakai... 50 Pentacontakai... 60 Hexacontakai... 70 Heptacontakai... 80 Octacontakai... 90 Enneacontakai... + Sides Suffix +1 ...henagon +2 ...digon +3 ...trigon +4 ...tetragon +5 ...pentagon +6 ...hexagon +7 ...heptagon +8 ...octagon +9 ...enneagon Examples:  46 sided polygon - Tetracontakaihexagon 28 sided polygon - Icosikaioctagon However, many people use the form n-gon, as in 46-gon, or 28-gon instead of these names. Credit to http://www.math.com