3Calculate the area of a triangle using the formula from the length of the sides.
Enter side a, side b and side c and click the button "Calculate the area of a triangle", Area of a triangle is displayed is calculated from the length of the three sides.
![Area of triangle(The length of the three sides)](/img/area_en/triangle_three_side.png)
![Formula of the area from the length of the sides of a triangle](/img/area_en/triangle_three_side1.jpg)
![Heron's formula](/img/area_en/triangle_three_side2.jpg)
Area of a triangle whose side a is 3, side b is 4, and side c is 5.
Area S: 6