# 3 8 8 triangle

### Acute isosceles triangle.

Sides: a = 3   b = 8   c = 8

Area: T = 11.78771752341
Perimeter: p = 19
Semiperimeter: s = 9.5

Angle ∠ A = α = 21.61438457497° = 21°36'50″ = 0.37772327724 rad
Angle ∠ B = β = 79.19330771251° = 79°11'35″ = 1.38221799406 rad
Angle ∠ C = γ = 79.19330771251° = 79°11'35″ = 1.38221799406 rad

Height: ha = 7.85881168228
Height: hb = 2.94767938085
Height: hc = 2.94767938085

Median: ma = 7.85881168228
Median: mb = 4.52876925691
Median: mc = 4.52876925691

Inradius: r = 1.24107552878
Circumradius: R = 4.0722222483

Vertex coordinates: A[8; 0] B[0; 0] C[0.56325; 2.94767938085]
Centroid: CG[2.85441666667; 0.98222646028]
Coordinates of the circumscribed circle: U[4; 0.76435417156]
Coordinates of the inscribed circle: I[1.5; 1.24107552878]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 158.386615425° = 158°23'10″ = 0.37772327724 rad
∠ B' = β' = 100.8076922875° = 100°48'25″ = 1.38221799406 rad
∠ C' = γ' = 100.8076922875° = 100°48'25″ = 1.38221799406 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.