# Sector Command

From GeoGebra Manual

Revision as of 11:27, 30 July 2015 by Markus.winkler (talk | contribs)

- Sector[ <Conic>, <Point>, <Point> ]
- Yields a conic sector between two points on the conic section.
**Example:**- Let
`c: x^2 + 2y^2 = 8`

be an ellipse,`D = (-2.83, 0)`

and`E = (0, -2)`

two points on the ellipse.`Sector[ c, D, E ]`

yields*d = 4.44*. - Let
`c: x^2 + y^2 = 9`

be a circle,`A = (3, 0)`

and`B = (0, 3)`

two points on the circle.`Sector[ c, A, B ]`

yields*d = 7.07*

- Let

**Note:**This works only for a circle or ellipse.

- Sector[ <Conic>, <Parameter Value>, <Parameter Value> ]
- Yields a conic sector between two parameter values between
*0*and*2π*on the conic section. **Example:**Let`c: x^2 + y^2 = 9`

be a circle.`Sector[ c, 0, 3/4 π ]`

yields*d = 10.6*

**Note:**Internally the following parametric forms are used:- Circle:
*(r cos(t), r sin(t))*where*r*is the circle's radius. - Ellipse:
*(a cos(t), b sin(t))*where*a*and*b*are the lengths of the semimajor and semiminor axes.

- Circle: