# 4 10 12 triangle

### Obtuse scalene triangle.

Sides: a = 4   b = 10   c = 12

Area: T = 18.73549939952
Perimeter: p = 26
Semiperimeter: s = 13

Angle ∠ A = α = 18.19548723388° = 18°11'42″ = 0.31875604293 rad
Angle ∠ B = β = 51.31878125465° = 51°19'4″ = 0.89656647939 rad
Angle ∠ C = γ = 110.4877315115° = 110°29'14″ = 1.92883674304 rad

Height: ha = 9.36774969976
Height: hb = 3.7476998799
Height: hc = 3.12224989992

Median: ma = 10.86327804912
Median: mb = 7.41661984871
Median: mc = 4.69904157598

Inradius: r = 1.44111533842
Circumradius: R = 6.40551261522

Vertex coordinates: A[12; 0] B[0; 0] C[2.5; 3.12224989992]
Centroid: CG[4.83333333333; 1.04108329997]
Coordinates of the circumscribed circle: U[6; -2.24217941533]
Coordinates of the inscribed circle: I[3; 1.44111533842]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 161.8055127661° = 161°48'18″ = 0.31875604293 rad
∠ B' = β' = 128.6822187453° = 128°40'56″ = 0.89656647939 rad
∠ C' = γ' = 69.51326848853° = 69°30'46″ = 1.92883674304 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.