Francais | English | Espanõl

List of centroids

From Wikipedia, the free encyclopedia

Jump to: navigation, search
Shape Figure <math>\bar x</math> <math>\bar y</math> Area
Triangular area Image:Triangle centroid 1.PNG Image:Triangle centroid 2.PNG   <math>\frac{h}{3}</math> <math>\frac{bh}{2}</math>
Quarter-circular area Image:Quarter-circle-centroid.png <math>\frac{4r}{3\pi}</math> <math>\frac{4r}{3\pi}</math> <math>\frac{\pi r^2}{4}</math>
Semicircular area Image:Semicircle-centroid.png <math>\frac{}{}0</math> <math>\frac{4r}{3\pi}</math> <math>\frac{\pi r^2}{2}</math>
Quarter-elliptical area Image:Elliptical-quarter.png <math>\frac{4a}{3\pi}</math> <math>\frac{4b}{3\pi}</math> <math>\frac{\pi a b}{4}</math>
Semielliptical area The area inside the ellipse <math>\frac{x^2}{a^2} + \frac{y^2}{b^2} = 1</math> and above the <math>\frac{}{}x</math> axis <math>\frac{}{}0</math> <math>\frac{4b}{3\pi}</math> <math>\frac{\pi a b}{2}</math>
Semiparabolic area The area between the curve <math>y = \frac{h}{b^2} x^2 </math> and the <math>\frac{}{}y</math> axis, from <math>\frac{}{}x = 0</math> to <math>\frac{}{}x = b</math> <math>\frac{3b}{8}</math> <math>\frac{3h}{5}</math> <math>\frac{2bh}{3}</math>
Parabolic area The area between the curve <math>\frac{}{}y = \frac{h}{b^2} x^2 </math> and the line <math>\frac{}{}y = h</math> <math>\frac{}{}0</math> <math>\frac{3h}{5}</math> <math>\frac{4bh}{3}</math>
Parabolic spandrel The area between the curve <math>\frac{}{}y = \frac{h}{b^2} x^2 </math> and the <math>\frac{}{}x</math> axis, from <math>\frac{}{}x = 0</math> to <math>\frac{}{}x = b</math> <math>\frac{3b}{4}</math> <math>\frac{3h}{10}</math> <math>\frac{bh}{3}</math>
General spandrel The area between the curve <math>y = \frac{h}{b^n} x^n</math> and the <math>\frac{}{}x</math> axis, from <math>\frac{}{}x = 0</math> to <math>\frac{}{}x = b</math> <math>\frac{n + 1}{n + 2} b</math> <math>\frac{n + 1}{4n + 2} h</math> <math>\frac{bh}{n + 1} b</math>
Circular sector The area between the curve (in polar coordinates) <math>\frac{}{}r = \rho</math> and the pole, from <math>\frac{}{}\theta = -\alpha</math> to <math>\frac{}{}\theta = \alpha</math> <math>\frac{2\rho\sin(\alpha)}{3\alpha}</math> <math>\frac{}{}0</math> <math>\frac{}{}\alpha \rho^2</math>
Quarter-circular arc The points on the circle <math>\frac{}{}x^2 + y^2 = r^2</math> and in the first quadrant <math>\frac{2r}{\pi}</math> <math>\frac{2r}{\pi}</math> <math>\frac{\pi r}{2}</math>
Semicircular arc The points on the circle <math>\frac{}{}x^2 + y^2 = r^2</math> and above the <math>\frac{}{}x</math> axis <math>\frac{}{}0</math> <math>\frac{2r}{\pi}</math> <math>\frac{}{}\pi r</math>
Arc of circle The points on the curve (in polar coordinates) <math>\frac{}{}r = \rho</math>, from <math>\frac{}{}\theta = -\alpha</math> to <math>\frac{}{}\theta = \alpha</math> <math>\frac{\rho\sin(\alpha)}{\alpha}</math> <math>\frac{}{}0</math> <math>\frac{}{}2\alpha \rho</math>

[edit] See also

[edit] External link

Personal tools