# GEOMETRIC FORMULAS

 GEOMETRIC FORMULAS Circle Area = ½ diameter x ½ circumference Area of sector = Length of arc x ½ radius Area of segment which is greater than semicircle = Area of sector of equal radius plus area of triangle Area of segment which is less than semicircle = Area of sector of equal radius minus area of triangle Circumference = Diameter x 3.1416 radius x 6.283185 Diameter = Circumference x .31 83 Radius = Circumference x .0159155 Cylinder or Prism Surface = ( area of both ends) + ( length x circumference) Ellipse Area = Product of the two diameters x .7854 Parabola Area = 2/3 altitude x base Parallelogram Area = altitude x base Polygon ( Regular) Area = Sum of sides x perpendicular from center to one of sides / 2
 Pyramid or Cone Surface = Circumference of base x ½ slant height + area of base

 Rectangle Area = Length x width Sphere Circumference = Cube root of solidity x 3.8978 square root of surface x 1.772454 Contents = Diameter x .5236 Contents of Segment = (height squared + three times the square of radius of base) x ( height x .5236) Diameter = Square root of surface x .56419 cube root of solidity x 1.2407 Surface = Circumference x diamter Volume = Surface x 1/ 6 diameter diameter cubed x .5236 radius cubed x 4.1888 circumference cubed x .016887 Square Area = Length x width Trapezium Area = Divide trapezium into two triangles; add their areas Trapezoid Area = Altitude x ½ sum of parallel sides
 Triangle Area = ½ altitude x base Wedge Contents = ½ altitude x area of base