# 13 20 27 triangle

### Obtuse scalene triangle.

Sides: a = 13   b = 20   c = 27

Area: T = 123.6933168769
Perimeter: p = 60
Semiperimeter: s = 30

Angle ∠ A = α = 27.26660444507° = 27°15'58″ = 0.47658822497 rad
Angle ∠ B = β = 44.81437424099° = 44°48'49″ = 0.78221473552 rad
Angle ∠ C = γ = 107.9220213139° = 107°55'13″ = 1.88435630487 rad

Height: ha = 19.03297182721
Height: hb = 12.36993168769
Height: hc = 9.16224569458

Median: ma = 22.85327897641
Median: mb = 18.68215416923
Median: mc = 10.11218742081

Inradius: r = 4.12331056256
Circumradius: R = 14.18883340646

Vertex coordinates: A[27; 0] B[0; 0] C[9.22222222222; 9.16224569458]
Centroid: CG[12.07440740741; 3.05441523153]
Coordinates of the circumscribed circle: U[13.5; -4.36656412507]
Coordinates of the inscribed circle: I[10; 4.12331056256]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 152.7343955549° = 152°44'2″ = 0.47658822497 rad
∠ B' = β' = 135.186625759° = 135°11'11″ = 0.78221473552 rad
∠ C' = γ' = 72.08797868606° = 72°4'47″ = 1.88435630487 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.