# 5 12 16 triangle

### Obtuse scalene triangle.

Sides: a = 5   b = 12   c = 16

Area: T = 20.66224659709
Perimeter: p = 33
Semiperimeter: s = 16.5

Angle ∠ A = α = 12.42992571325° = 12°25'45″ = 0.21769314605 rad
Angle ∠ B = β = 31.10218950348° = 31°6'7″ = 0.5432830472 rad
Angle ∠ C = γ = 136.4698847833° = 136°28'8″ = 2.38218307211 rad

Height: ha = 8.26549863884
Height: hb = 3.44437443285
Height: hc = 2.58328082464

Median: ma = 13.91994109071
Median: mb = 10.22325241501
Median: mc = 4.52876925691

Inradius: r = 1.25222706649
Circumradius: R = 11.61552641383

Vertex coordinates: A[16; 0] B[0; 0] C[4.281125; 2.58328082464]
Centroid: CG[6.76604166667; 0.86109360821]
Coordinates of the circumscribed circle: U[8; -8.42110665002]
Coordinates of the inscribed circle: I[4.5; 1.25222706649]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 167.5710742867° = 167°34'15″ = 0.21769314605 rad
∠ B' = β' = 148.8988104965° = 148°53'53″ = 0.5432830472 rad
∠ C' = γ' = 43.53111521674° = 43°31'52″ = 2.38218307211 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.