Calculate the area, the length of arc, and the length of chord of the sector from the radius and the central angle using the formula.
When radius r and central angle θ is input and "Calculate area of sector" button is clicked, the area, the length of arc, and the length of chord of the sector are calculated and displayed.
![Area of fan shape](/img/area_en/sector.png)
![Formula for area of sector](/img/area_en/sector1.jpg)
![Formula for length of arc of sector](/img/area_en/sector2.jpg)
![Formula for length of chord of sector](/img/area_en/sector3.jpg)
Area of a sector of the radius r is 1, and a central angle θ is 60°
Area S: 0.5235987755983
Circular arc length L: 1.0471975511966
Length of chord a: 1
Circular arc length L: 1.0471975511966
Length of chord a: 1