Calculatrice de Triangle Avancée Gratuite
Calculez toutes les propriétés d'un triangle : aire, périmètre, angles, hauteurs et médianes. Utilisez différentes méthodes.
Area (Heron's)
14.6969
Formule
Triangle Area via Heron's Formula
Formula
s = (a + b + c) / 2 (semi-perimeter)
Area = sqrt(s × (s-a) × (s-b) × (s-c))
Heron's formula computes the area of any triangle when you know all three side lengths, without needing height or angles.
Inradius
The inradius (radius of the inscribed circle) is: r = Area / s
Exemple Résolu
Triangle with sides 5, 6, 7.
- 01s = (5+6+7)/2 = 9
- 02Area = √(9 × 4 × 3 × 2) = √216 ≈ 14.6969
- 03Inradius = 14.6969 / 9 ≈ 1.6330
Questions Fréquentes
What is Heron's formula?
Heron's formula calculates the area of a triangle from the lengths of its three sides, using the semi-perimeter. No angles or heights are needed.
When does Heron's formula not work?
The three sides must satisfy the triangle inequality (each side must be less than the sum of the other two). If not, the three lengths cannot form a triangle.
What is the inradius?
The inradius is the radius of the largest circle that fits entirely inside the triangle (the inscribed circle). It equals the area divided by the semi-perimeter.
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