A table of formulas for geometry, related to area and perimeter of triangles, rectangles, cercles, sectors, and volume of sphere, cone, cylinder are presented.

Right Triangle and Pythagora's theorem Pythagora's theorem: The two sides a and b of a right triangle and the hypotenuse c are related by a 2 + b 2 = c 2 Area and Perimeter of Triangle Perimeter = a + b + c There are several formulas for the area. If the base b and the corresponding height h are known, we use the formula Area = (1 / 2) * b * h. If two sides and the angle between them are known, we use one of the formulas, depending on which side and which angle are known Area = (1 / 2)* b * c sin A Area = (1 / 2)* a * c sin B Area = (1 / 2)* a * b sin C . If all three sides are known, we may use Heron's formula for the area. Area = sqrt [ s(s - a)(s - b)(s - c) ] , where s = (a + b + c)/2. Area and Perimeter of Rectangle Perimeter = 2L + 2W Area = L * W Area of Parallelogram Area = b * h Area of Trapezoid Area = (1 / 2)(a + b) * h Circumference of a Circle and Area of a Circular Region Circumference = 2*Pi*r Area = Pi*r 2 Arclength and Area of a Circular Sector Arclength: s = r*t Area = (1/2) *r 2 * t where t is the central angle in RADIANS. Volume and Surface Area of a Rectangular Solid Volume = L*W*H Surface Area = 2(L*W + H*W + H*L) Volume and Surface Area of a Sphere Volume = (4/3)* Pi * r 3 Surface Area = 4 * Pi * r 2 Volume and Surface Area of a Right Circular Cylinder Volume = Pi * r 2 * h Surface Area = 2 * Pi * r * h Volume and Surface Area of a Right Circular Cone Volume = (1/3)* Pi * r 2 * h Surface Area = Pi * r * sqrt (r 2 + h 2) See also area of regular polygons. More geometry references Geometry Tutorials, Problems and Interactive Applets. Area, Perimeter and Diagonal of a Rectangle - Geometry Calculator. Length and Width of Rectangle - Geometry Calculator.