# 15 20 27 triangle

### Obtuse scalene triangle.

Sides: a = 15   b = 20   c = 27

Area: T = 147.7299482501
Perimeter: p = 62
Semiperimeter: s = 31

Angle ∠ A = α = 33.17114519508° = 33°10'17″ = 0.57989510542 rad
Angle ∠ B = β = 46.84768650693° = 46°50'49″ = 0.81876320397 rad
Angle ∠ C = γ = 99.98216829799° = 99°58'54″ = 1.74550095597 rad

Height: ha = 19.69772643335
Height: hb = 14.77329482501
Height: hc = 10.94329246297

Median: ma = 22.54444006352
Median: mb = 19.41664878389
Median: mc = 11.41327122105

Inradius: r = 4.76554671775
Circumradius: R = 13.70774872647

Vertex coordinates: A[27; 0] B[0; 0] C[10.25992592593; 10.94329246297]
Centroid: CG[12.42197530864; 3.64876415432]
Coordinates of the circumscribed circle: U[13.5; -2.37659644592]
Coordinates of the inscribed circle: I[11; 4.76554671775]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 146.8298548049° = 146°49'43″ = 0.57989510542 rad
∠ B' = β' = 133.1533134931° = 133°9'11″ = 0.81876320397 rad
∠ C' = γ' = 80.01883170201° = 80°1'6″ = 1.74550095597 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.