# 7 8 8 triangle

### Acute isosceles triangle.

Sides: a = 7   b = 8   c = 8

Area: T = 25.17881154974
Perimeter: p = 23
Semiperimeter: s = 11.5

Angle ∠ A = α = 51.88989595447° = 51°53'20″ = 0.90656331895 rad
Angle ∠ B = β = 64.05655202276° = 64°3'20″ = 1.1187979732 rad
Angle ∠ C = γ = 64.05655202276° = 64°3'20″ = 1.1187979732 rad

Height: ha = 7.1943747285
Height: hb = 6.29545288743
Height: hc = 6.29545288743

Median: ma = 7.1943747285
Median: mb = 6.36439610307
Median: mc = 6.36439610307

Inradius: r = 2.18994013476
Circumradius: R = 4.44883074999

Vertex coordinates: A[8; 0] B[0; 0] C[3.06325; 6.29545288743]
Centroid: CG[3.68875; 2.09881762914]
Coordinates of the circumscribed circle: U[4; 1.94661345312]
Coordinates of the inscribed circle: I[3.5; 2.18994013476]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 128.1111040455° = 128°6'40″ = 0.90656331895 rad
∠ B' = β' = 115.9444479772° = 115°56'40″ = 1.1187979732 rad
∠ C' = γ' = 115.9444479772° = 115°56'40″ = 1.1187979732 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.