# 9 14 20 triangle

### Obtuse scalene triangle.

Sides: a = 9   b = 14   c = 20

Area: T = 54.98657936198
Perimeter: p = 43
Semiperimeter: s = 21.5

Angle ∠ A = α = 23.12660741872° = 23°7'34″ = 0.40436261376 rad
Angle ∠ B = β = 37.65884620062° = 37°39'30″ = 0.65772641532 rad
Angle ∠ C = γ = 119.2155463807° = 119°12'56″ = 2.08107023627 rad

Height: ha = 12.21990652488
Height: hb = 7.85551133743
Height: hc = 5.4998579362

Median: ma = 16.66658333125
Median: mb = 13.83883525031
Median: mc = 6.2054836823

Inradius: r = 2.5577478773
Circumradius: R = 11.45875049031

Vertex coordinates: A[20; 0] B[0; 0] C[7.125; 5.4998579362]
Centroid: CG[9.04216666667; 1.83328597873]
Coordinates of the circumscribed circle: U[10; -5.59223535837]
Coordinates of the inscribed circle: I[7.5; 2.5577478773]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 156.8743925813° = 156°52'26″ = 0.40436261376 rad
∠ B' = β' = 142.3421537994° = 142°20'30″ = 0.65772641532 rad
∠ C' = γ' = 60.78545361934° = 60°47'4″ = 2.08107023627 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.