# 2 8 8 triangle

### Acute isosceles triangle.

Sides: a = 2   b = 8   c = 8

Area: T = 7.93772539332
Perimeter: p = 18
Semiperimeter: s = 9

Angle ∠ A = α = 14.36215115629° = 14°21'41″ = 0.25106556623 rad
Angle ∠ B = β = 82.81992442185° = 82°49'9″ = 1.44554684956 rad
Angle ∠ C = γ = 82.81992442185° = 82°49'9″ = 1.44554684956 rad

Height: ha = 7.93772539332
Height: hb = 1.98443134833
Height: hc = 1.98443134833

Median: ma = 7.93772539332
Median: mb = 4.24326406871
Median: mc = 4.24326406871

Inradius: r = 0.88219171037
Circumradius: R = 4.03216210454

Vertex coordinates: A[8; 0] B[0; 0] C[0.25; 1.98443134833]
Centroid: CG[2.75; 0.66114378278]
Coordinates of the circumscribed circle: U[4; 0.50439526307]
Coordinates of the inscribed circle: I[1; 0.88219171037]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 165.6388488437° = 165°38'19″ = 0.25106556623 rad
∠ B' = β' = 97.18107557815° = 97°10'51″ = 1.44554684956 rad
∠ C' = γ' = 97.18107557815° = 97°10'51″ = 1.44554684956 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.