# 9 25 28 triangle

### Obtuse scalene triangle.

Sides: a = 9   b = 25   c = 28

Area: T = 110.7977111876
Perimeter: p = 62
Semiperimeter: s = 31

Angle ∠ A = α = 18.45552071689° = 18°27'19″ = 0.32221041292 rad
Angle ∠ B = β = 61.56331098511° = 61°33'47″ = 1.07444789647 rad
Angle ∠ C = γ = 99.98216829799° = 99°58'54″ = 1.74550095597 rad

Height: ha = 24.62215804168
Height: hb = 8.86437689501
Height: hc = 7.91440794197

Median: ma = 26.15881727191
Median: mb = 16.62107701386
Median: mc = 12.53299640861

Inradius: r = 3.57441003831
Circumradius: R = 14.21551719782

Vertex coordinates: A[28; 0] B[0; 0] C[4.28657142857; 7.91440794197]
Centroid: CG[10.76219047619; 2.63880264732]
Coordinates of the circumscribed circle: U[14; -2.46439631429]
Coordinates of the inscribed circle: I[6; 3.57441003831]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 161.5454792831° = 161°32'41″ = 0.32221041292 rad
∠ B' = β' = 118.4376890149° = 118°26'13″ = 1.07444789647 rad
∠ C' = γ' = 80.01883170201° = 80°1'6″ = 1.74550095597 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.