# 13 18 27 triangle

### Obtuse scalene triangle.

Sides: a = 13   b = 18   c = 27

Area: T = 101.0354647522
Perimeter: p = 58
Semiperimeter: s = 29

Angle ∠ A = α = 24.56884742814° = 24°34'6″ = 0.42988007684 rad
Angle ∠ B = β = 35.14883878921° = 35°8'54″ = 0.61334550955 rad
Angle ∠ C = γ = 120.2833137827° = 120°16'59″ = 2.09993367897 rad

Height: ha = 15.54437919265
Height: hb = 11.22660719469
Height: hc = 7.48440479646

Median: ma = 22.00656810847
Median: mb = 19.18333260933
Median: mc = 8.01656097709

Inradius: r = 3.48439533628
Circumradius: R = 15.63332509563

Vertex coordinates: A[27; 0] B[0; 0] C[10.63296296296; 7.48440479646]
Centroid: CG[12.54332098765; 2.49546826549]
Coordinates of the circumscribed circle: U[13.5; -7.88334342429]
Coordinates of the inscribed circle: I[11; 3.48439533628]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 155.4321525719° = 155°25'54″ = 0.42988007684 rad
∠ B' = β' = 144.8521612108° = 144°51'6″ = 0.61334550955 rad
∠ C' = γ' = 59.71768621735° = 59°43'1″ = 2.09993367897 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.