# 10 10 19 triangle

### Obtuse isosceles triangle.

Sides: a = 10   b = 10   c = 19

Area: T = 29.66437404924
Perimeter: p = 39
Semiperimeter: s = 19.5

Angle ∠ A = α = 18.19548723388° = 18°11'42″ = 0.31875604293 rad
Angle ∠ B = β = 18.19548723388° = 18°11'42″ = 0.31875604293 rad
Angle ∠ C = γ = 143.6110255322° = 143°36'37″ = 2.5066471795 rad

Height: ha = 5.93327480985
Height: hb = 5.93327480985
Height: hc = 3.12224989992

Median: ma = 14.33552711868
Median: mb = 14.33552711868
Median: mc = 3.12224989992

Inradius: r = 1.52112174611
Circumradius: R = 16.01328153805

Vertex coordinates: A[19; 0] B[0; 0] C[9.5; 3.12224989992]
Centroid: CG[9.5; 1.04108329997]
Coordinates of the circumscribed circle: U[9.5; -12.89903163813]
Coordinates of the inscribed circle: I[9.5; 1.52112174611]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 161.8055127661° = 161°48'18″ = 0.31875604293 rad
∠ B' = β' = 161.8055127661° = 161°48'18″ = 0.31875604293 rad
∠ C' = γ' = 36.39897446775° = 36°23'23″ = 2.5066471795 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.