Geometry Formulas

Geometry formulas contains various concepts related formulas of mathematical stream geometry like slope , section formula , midpoint formula , etc.

1) Distance Formula

In the figure , `A (x_1, y_1)` and `B(x_2, y_2)` are anyt wo points in the XY plane, distance between A and B is given by ,

`d(A,B)=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}`

This is Distance formula.

Note : Co-ordinates of origin are `(0, 0)` and  if co-ordinates of point A are $(x, y)$ then distance between origin and point A is 

`d(O, A) =\sqrt{ x_2 + y_2}`.


2) Section Formula 


In the figure , point P on the seg AB in `XY` plane, divides seg `AB` in the ratio `m : n` and assume `A(x_1,y_1),  B(x_2,y_2)` and  `P(x, y)` 

So, co-ordinates of the point P, which divides the line segment joining the points `A(x_1, y_1)` and `B(x_2, y_2)` in the ratio `m : n` are given by ,

`(\frac{mx_2+nx_1}{m+n},\frac{my_2+ny_1}{m+n})$`


3) Midpoint Formula


If `A(x_1, y_1)` and `B(x_2, y_2)`  are two points and `P (x, y)` is the midpoint of seg `AB` then `m = n`, the co-ordinates of midpoint P is,

`x=\frac{x_1+x_2}{2}` and `y=\frac{y_1+y_2}{2}`


4) Centroid Formula

In `\triangle ABC `, `A(x_1, y_1), B(x_2, y_2), C(x_3, y_3)` are the vertices. Seg `AD is a median and `G(x, y)` is the centroid, then

So co-ordinates of the centroid G are `(\frac{x_1+x_2+x_3}{3},\frac{y_1+y_2+y_3}{3})`


5) Slope Formula

If ` A(x_1, y_1)` and `B(x_2, y_2)`  are any two points on line l$, the ratio `\frac{y_2-y_1}{x_2-x_1}`  is called the slope of the line `l`.

Generally slope is shown by letter `m`.

`m=\frac{y_2-y_1}{x_2-x_1}`

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