# 5 26 28 triangle

### Obtuse scalene triangle.

Sides: a = 5   b = 26   c = 28

Area: T = 61.59990056738
Perimeter: p = 59
Semiperimeter: s = 29.5

Angle ∠ A = α = 9.74329385734° = 9°44'35″ = 0.17700463569 rad
Angle ∠ B = β = 61.64106499718° = 61°38'26″ = 1.07658322951 rad
Angle ∠ C = γ = 108.6166411455° = 108°36'59″ = 1.89657140016 rad

Height: ha = 24.64396022695
Height: hb = 4.73883850518
Height: hc = 4.43999289767

Median: ma = 26.90326021046
Median: mb = 15.34660092532
Median: mc = 12.43298028947

Inradius: r = 2.08881018872
Circumradius: R = 14.77329657329

Vertex coordinates: A[28; 0] B[0; 0] C[2.375; 4.43999289767]
Centroid: CG[10.125; 1.46766429922]
Coordinates of the circumscribed circle: U[14; -4.71659852147]
Coordinates of the inscribed circle: I[3.5; 2.08881018872]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 170.2577061427° = 170°15'25″ = 0.17700463569 rad
∠ B' = β' = 118.3599350028° = 118°21'34″ = 1.07658322951 rad
∠ C' = γ' = 71.38435885453° = 71°23'1″ = 1.89657140016 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    