# 7 14 14 triangle

### Acute isosceles triangle.

Sides: a = 7   b = 14   c = 14

Area: T = 47.4444045991
Perimeter: p = 35
Semiperimeter: s = 17.5

Angle ∠ A = α = 28.95550243719° = 28°57'18″ = 0.50553605103 rad
Angle ∠ B = β = 75.52224878141° = 75°31'21″ = 1.31881160717 rad
Angle ∠ C = γ = 75.52224878141° = 75°31'21″ = 1.31881160717 rad

Height: ha = 13.55554417117
Height: hb = 6.77877208559
Height: hc = 6.77877208559

Median: ma = 13.55554417117
Median: mb = 8.57332140997
Median: mc = 8.57332140997

Inradius: r = 2.71110883423
Circumradius: R = 7.23295689129

Vertex coordinates: A[14; 0] B[0; 0] C[1.75; 6.77877208559]
Centroid: CG[5.25; 2.25992402853]
Coordinates of the circumscribed circle: U[7; 1.80773922282]
Coordinates of the inscribed circle: I[3.5; 2.71110883423]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 151.0454975628° = 151°2'42″ = 0.50553605103 rad
∠ B' = β' = 104.4787512186° = 104°28'39″ = 1.31881160717 rad
∠ C' = γ' = 104.4787512186° = 104°28'39″ = 1.31881160717 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    