# 6 19 21 triangle

### Obtuse scalene triangle.

Sides: a = 6   b = 19   c = 21

Area: T = 55.92985258164
Perimeter: p = 46
Semiperimeter: s = 23

Angle ∠ A = α = 16.28107061966° = 16°16'51″ = 0.28441519277 rad
Angle ∠ B = β = 62.59224054672° = 62°35'33″ = 1.09224435621 rad
Angle ∠ C = γ = 101.1276888336° = 101°7'37″ = 1.76549971638 rad

Height: ha = 18.64328419388
Height: hb = 5.88772132438
Height: hc = 5.32765262682

Median: ma = 19.79989898732
Median: mb = 12.17657956619
Median: mc = 9.3944147114

Inradius: r = 2.43216750355
Circumradius: R = 10.70111581525

Vertex coordinates: A[21; 0] B[0; 0] C[2.76219047619; 5.32765262682]
Centroid: CG[7.92106349206; 1.77655087561]
Coordinates of the circumscribed circle: U[10.5; -2.06551357838]
Coordinates of the inscribed circle: I[4; 2.43216750355]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 163.7199293803° = 163°43'9″ = 0.28441519277 rad
∠ B' = β' = 117.4087594533° = 117°24'27″ = 1.09224435621 rad
∠ C' = γ' = 78.87331116638° = 78°52'23″ = 1.76549971638 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.