# 14 15 21 triangle

### Obtuse scalene triangle.

Sides: a = 14   b = 15   c = 21

Area: T = 104.8810884817
Perimeter: p = 50
Semiperimeter: s = 25

Angle ∠ A = α = 41.7522205202° = 41°45'8″ = 0.72987134507 rad
Angle ∠ B = β = 45.51883921612° = 45°31'6″ = 0.79444458134 rad
Angle ∠ C = γ = 92.72994026368° = 92°43'46″ = 1.61884333894 rad

Height: ha = 14.98329835453
Height: hb = 13.98441179756
Height: hc = 9.98986556969

Median: ma = 16.85222995464
Median: mb = 16.19441347407
Median: mc = 10.01224921973

Inradius: r = 4.19552353927
Circumradius: R = 10.51219250464

Vertex coordinates: A[21; 0] B[0; 0] C[9.81095238095; 9.98986556969]
Centroid: CG[10.27698412698; 3.3329551899]
Coordinates of the circumscribed circle: U[10.5; -0.50105678594]
Coordinates of the inscribed circle: I[10; 4.19552353927]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 138.2487794798° = 138°14'52″ = 0.72987134507 rad
∠ B' = β' = 134.4821607839° = 134°28'54″ = 0.79444458134 rad
∠ C' = γ' = 87.27105973632° = 87°16'14″ = 1.61884333894 rad

# How did we calculate this triangle?

Now we know the lengths of all three sides of the triangle and the triangle is uniquely determined. Next we calculate another its characteristics - same procedure as calculation of the triangle from the known three sides SSS. ### 1. The triangle circumference is the sum of the lengths of its three sides ### 2. Semiperimeter of the triangle ### 3. The triangle area using Heron's formula ### 4. Calculate the heights of the triangle from its area. ### 5. Calculation of the inner angles of the triangle using a Law of Cosines ### 6. Inradius ### 7. Circumradius ### 8. Calculation of medians #### Look also our friend's collection of math examples and problems:

See more informations about triangles or more information about solving triangles.