# 21 26 27 triangle

### Acute scalene triangle.

Sides: a = 21   b = 26   c = 27

Area: T = 255.1866206524
Perimeter: p = 74
Semiperimeter: s = 37

Angle ∠ A = α = 46.63876682605° = 46°38'16″ = 0.81439808666 rad
Angle ∠ B = β = 64.17548595695° = 64°10'29″ = 1.12200625965 rad
Angle ∠ C = γ = 69.187747217° = 69°11'15″ = 1.20875491905 rad

Height: ha = 24.30334482404
Height: hb = 19.63297081941
Height: hc = 18.90326819647

Median: ma = 24.33661870473
Median: mb = 20.39660780544
Median: mc = 19.39771647413

Inradius: r = 6.89769245006
Circumradius: R = 14.44223950268

Vertex coordinates: A[27; 0] B[0; 0] C[9.14881481481; 18.90326819647]
Centroid: CG[12.0499382716; 6.30108939882]
Coordinates of the circumscribed circle: U[13.5; 5.13215469509]
Coordinates of the inscribed circle: I[11; 6.89769245006]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 133.3622331739° = 133°21'44″ = 0.81439808666 rad
∠ B' = β' = 115.8255140431° = 115°49'31″ = 1.12200625965 rad
∠ C' = γ' = 110.813252783° = 110°48'45″ = 1.20875491905 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.