# 7 26 30 triangle

### Obtuse scalene triangle.

Sides: a = 7   b = 26   c = 30

Area: T = 79.79330918062
Perimeter: p = 63
Semiperimeter: s = 31.5

Angle ∠ A = α = 11.80659481286° = 11°48'21″ = 0.20660526662 rad
Angle ∠ B = β = 49.45883981265° = 49°27'30″ = 0.86332118901 rad
Angle ∠ C = γ = 118.7365653745° = 118°44'8″ = 2.07223280974 rad

Height: ha = 22.79880262304
Height: hb = 6.13879301389
Height: hc = 5.32195394537

Median: ma = 27.85222889544
Median: mb = 17.47985582929
Median: mc = 11.72660393996

Inradius: r = 2.53331140256
Circumradius: R = 17.1076744069

Vertex coordinates: A[30; 0] B[0; 0] C[4.55; 5.32195394537]
Centroid: CG[11.51766666667; 1.77331798179]
Coordinates of the circumscribed circle: U[15; -8.2244396187]
Coordinates of the inscribed circle: I[5.5; 2.53331140256]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 168.1944051871° = 168°11'39″ = 0.20660526662 rad
∠ B' = β' = 130.5421601874° = 130°32'30″ = 0.86332118901 rad
∠ C' = γ' = 61.26443462551° = 61°15'52″ = 2.07223280974 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    