# 16 20 26 triangle

### Obtuse scalene triangle.

Sides: a = 16   b = 20   c = 26

Area: T = 159.9221855917
Perimeter: p = 62
Semiperimeter: s = 31

Angle ∠ A = α = 37.95880285807° = 37°57'29″ = 0.66224925763 rad
Angle ∠ B = β = 50.251118676° = 50°15'4″ = 0.8777048662 rad
Angle ∠ C = γ = 91.79107846593° = 91°47'27″ = 1.60220514153 rad

Height: ha = 19.99902319896
Height: hb = 15.99221855917
Height: hc = 12.30216812244

Median: ma = 21.77215410571
Median: mb = 19.13111264697
Median: mc = 12.61095202129

Inradius: r = 5.15987695457
Circumradius: R = 13.00663523092

Vertex coordinates: A[26; 0] B[0; 0] C[10.23107692308; 12.30216812244]
Centroid: CG[12.07769230769; 4.10105604081]
Coordinates of the circumscribed circle: U[13; -0.40664485097]
Coordinates of the inscribed circle: I[11; 5.15987695457]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 142.0421971419° = 142°2'31″ = 0.66224925763 rad
∠ B' = β' = 129.749881324° = 129°44'56″ = 0.8777048662 rad
∠ C' = γ' = 88.20992153407° = 88°12'33″ = 1.60220514153 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    