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 theoremPythagora's theorem: The two sidesa and b of a right triangle and the hypotenuse c are related by
a
^{ 2} + b^{ 2} = c^{ 2} ## Area and Perimeter of TrianglePerimeter = 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 = √ [ s(s - a)(s - b)(s - c) ] , where s = (a + b + c)/2.
## Area and Perimeter of RectanglePerimeter = 2L + 2W
Area = L × W
## Area of ParallelogramArea = b × h
## Area of TrapezoidArea = (1 / 2)(a + b) × h
## Circumference of a Circle and Area of a Circular RegionCircumference = 2 × ? × r
Area = ? × r
^{ 2}## Arclength and Area of a Circular SectorArclength: s = r × t
Area = (1/2) × r
^{ 2} × twhere t is the central angle in RADIANS.
## Volume and Surface Area of a Rectangular SolidVolume = L*W*H
Surface Area = 2(L × W + H × W + H × L)
## Volume and Surface Area of a SphereVolume = (4/3) × ? × r
^{ 3}Surface Area = 4 × ? × r
^{ 2}## Volume and Surface Area of a Right Circular CylinderVolume = ? × r
^{ 2} × hTotal Surface Area = 2 × ? × r × h + 2 × ? × r
^{ 2}## Volume and Surface Area of a Right Circular ConeVolume = (1/3) × ? × r
^{ 2} × hSurface Area = ? × r × √ (r
^{ 2} + h^{ 2})See also area of regular polygons.
## More References and Links to GeometryGeometry Tutorials, Problems and Interactive Applets.Area, Perimeter and Diagonal of a Rectangle - Geometry Calculator. Length and Width of Rectangle - Geometry Calculator. |