# 2 2 3 triangle

### Obtuse isosceles triangle.

Sides: a = 2   b = 2   c = 3

Area: T = 1.98443134833
Perimeter: p = 7
Semiperimeter: s = 3.5

Angle ∠ A = α = 41.41096221093° = 41°24'35″ = 0.72327342478 rad
Angle ∠ B = β = 41.41096221093° = 41°24'35″ = 0.72327342478 rad
Angle ∠ C = γ = 97.18107557815° = 97°10'51″ = 1.6966124158 rad

Height: ha = 1.98443134833
Height: hb = 1.98443134833
Height: hc = 1.32328756555

Median: ma = 2.34552078799
Median: mb = 2.34552078799
Median: mc = 1.32328756555

Inradius: r = 0.56769467095
Circumradius: R = 1.5121857892

Vertex coordinates: A[3; 0] B[0; 0] C[1.5; 1.32328756555]
Centroid: CG[1.5; 0.44109585518]
Coordinates of the circumscribed circle: U[1.5; -0.18989822365]
Coordinates of the inscribed circle: I[1.5; 0.56769467095]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 138.5990377891° = 138°35'25″ = 0.72327342478 rad
∠ B' = β' = 138.5990377891° = 138°35'25″ = 0.72327342478 rad
∠ C' = γ' = 82.81992442185° = 82°49'9″ = 1.6966124158 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    