# 11 23 28 triangle

### Obtuse scalene triangle.

Sides: a = 11   b = 23   c = 28

Area: T = 121.9843605456
Perimeter: p = 62
Semiperimeter: s = 31

Angle ∠ A = α = 22.26112954012° = 22°15'41″ = 0.38985329005 rad
Angle ∠ B = β = 52.38223203336° = 52°22'56″ = 0.91442439597 rad
Angle ∠ C = γ = 105.3566384265° = 105°21'23″ = 1.83988157934 rad

Height: ha = 22.17988373556
Height: hb = 10.60772700396
Height: hc = 8.71331146754

Median: ma = 25.02549875125
Median: mb = 17.89655301682
Median: mc = 11.35878166916

Inradius: r = 3.93549550147
Circumradius: R = 14.51883444397

Vertex coordinates: A[28; 0] B[0; 0] C[6.71442857143; 8.71331146754]
Centroid: CG[11.57114285714; 2.90443715585]
Coordinates of the circumscribed circle: U[14; -3.84547789623]
Coordinates of the inscribed circle: I[8; 3.93549550147]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 157.7398704599° = 157°44'19″ = 0.38985329005 rad
∠ B' = β' = 127.6187679666° = 127°37'4″ = 0.91442439597 rad
∠ C' = γ' = 74.64436157347° = 74°38'37″ = 1.83988157934 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.