How to calculate the angles and sides of a triangle?

A triangle is determined by 3 of the 6 free values, with at least one side. Fill in 3 of the 6 fields, with at least one side, and press the 'Calculate' button. (Note: if more than 3 fields are filled, only a third used to determine the triangle, the others are (eventualy) overwritten

• 3 sides
• 2 sides en 1 angle
• 1 side en 2 angles

For a triangle, following rules are always true:

• the sum of the 3 angles is excactly 180 degrees (or pi radians)
• the sum of two sides is always bigger than the third side

Formules

• Calculate the area (surface) of a triangle
• Law of sines
• Law of cosines
• Pythagorean theorem
• The formula of Heron