# 4 5 8 triangle

### Obtuse scalene triangle.

Sides: a = 4   b = 5   c = 8

Area: T = 8.1821534086
Perimeter: p = 17
Semiperimeter: s = 8.5

Angle ∠ A = α = 24.14768479965° = 24°8'49″ = 0.42114420015 rad
Angle ∠ B = β = 30.75435198081° = 30°45'13″ = 0.53767501772 rad
Angle ∠ C = γ = 125.1099632195° = 125°5'59″ = 2.18334004748 rad

Height: ha = 4.0910767043
Height: hb = 3.27326136344
Height: hc = 2.04553835215

Median: ma = 6.36439610307
Median: mb = 5.80994750193
Median: mc = 2.12113203436

Inradius: r = 0.96325334219
Circumradius: R = 4.88990586508

Vertex coordinates: A[8; 0] B[0; 0] C[3.43875; 2.04553835215]
Centroid: CG[3.81325; 0.68217945072]
Coordinates of the circumscribed circle: U[4; -2.81112087242]
Coordinates of the inscribed circle: I[3.5; 0.96325334219]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 155.8533152003° = 155°51'11″ = 0.42114420015 rad
∠ B' = β' = 149.2466480192° = 149°14'47″ = 0.53767501772 rad
∠ C' = γ' = 54.99003678046° = 54°54'1″ = 2.18334004748 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.