# 5 27 28 triangle

### Obtuse scalene triangle.

Sides: a = 5   b = 27   c = 28

Area: T = 67.0822039325
Perimeter: p = 60
Semiperimeter: s = 30

Angle ∠ A = α = 10.22221793906° = 10°13'20″ = 0.17884106871 rad
Angle ∠ B = β = 73.3988450401° = 73°23'54″ = 1.28110446254 rad
Angle ∠ C = γ = 96.37993702084° = 96°22'46″ = 1.68221373411 rad

Height: ha = 26.833281573
Height: hb = 4.969903995
Height: hc = 4.79215742375

Median: ma = 27.39106918496
Median: mb = 14.90880515159
Median: mc = 13.45436240471

Inradius: r = 2.23660679775
Circumradius: R = 14.08772282582

Vertex coordinates: A[28; 0] B[0; 0] C[1.42985714286; 4.79215742375]
Centroid: CG[9.81095238095; 1.59771914125]
Coordinates of the circumscribed circle: U[14; -1.56552475842]
Coordinates of the inscribed circle: I[3; 2.23660679775]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 169.7787820609° = 169°46'40″ = 0.17884106871 rad
∠ B' = β' = 106.6021549599° = 106°36'6″ = 1.28110446254 rad
∠ C' = γ' = 83.62106297916° = 83°37'14″ = 1.68221373411 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    