# 9 22 28 triangle

### Obtuse scalene triangle.

Sides: a = 9   b = 22   c = 28

Area: T = 82.48329527842
Perimeter: p = 59
Semiperimeter: s = 29.5

Angle ∠ A = α = 15.53435026063° = 15°32'1″ = 0.27111107648 rad
Angle ∠ B = β = 40.89113435638° = 40°53'29″ = 0.71436885808 rad
Angle ∠ C = γ = 123.575515383° = 123°34'31″ = 2.1576793308 rad

Height: ha = 18.33295450632
Height: hb = 7.49884502531
Height: hc = 5.89216394846

Median: ma = 24.77439782837
Median: mb = 17.64993625947
Median: mc = 9.30105376189

Inradius: r = 2.79660322978
Circumradius: R = 16.80334721505

Vertex coordinates: A[28; 0] B[0; 0] C[6.80435714286; 5.89216394846]
Centroid: CG[11.60111904762; 1.96438798282]
Coordinates of the circumscribed circle: U[14; -9.29328292954]
Coordinates of the inscribed circle: I[7.5; 2.79660322978]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 164.4666497394° = 164°27'59″ = 0.27111107648 rad
∠ B' = β' = 139.1098656436° = 139°6'31″ = 0.71436885808 rad
∠ C' = γ' = 56.425484617° = 56°25'29″ = 2.1576793308 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.