# 11 14 21 triangle

### Obtuse scalene triangle.

Sides: a = 11   b = 14   c = 21

Area: T = 70.48440407468
Perimeter: p = 46
Semiperimeter: s = 23

Angle ∠ A = α = 28.6521659028° = 28°39'6″ = 0.55000657862 rad
Angle ∠ B = β = 37.60876855758° = 37°36'28″ = 0.65663779374 rad
Angle ∠ C = γ = 113.7410655396° = 113°44'26″ = 1.985514893 rad

Height: ha = 12.81552801358
Height: hb = 10.06991486781
Height: hc = 6.71327657854

Median: ma = 16.97879268463
Median: mb = 15.23215462117
Median: mc = 6.94662219947

Inradius: r = 3.06545235107
Circumradius: R = 11.4710681752

Vertex coordinates: A[21; 0] B[0; 0] C[8.71442857143; 6.71327657854]
Centroid: CG[9.90547619048; 2.23875885951]
Coordinates of the circumscribed circle: U[10.5; -4.61880666794]
Coordinates of the inscribed circle: I[9; 3.06545235107]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 151.3488340972° = 151°20'54″ = 0.55000657862 rad
∠ B' = β' = 142.3922314424° = 142°23'32″ = 0.65663779374 rad
∠ C' = γ' = 66.25993446038° = 66°15'34″ = 1.985514893 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.