# 9 14 18 triangle

### Obtuse scalene triangle.

Sides: a = 9   b = 14   c = 18

Area: T = 61.8954567613
Perimeter: p = 41
Semiperimeter: s = 20.5

Angle ∠ A = α = 29.42112427193° = 29°25'16″ = 0.51334975555 rad
Angle ∠ B = β = 49.83296961902° = 49°49'47″ = 0.87696922638 rad
Angle ∠ C = γ = 100.749906109° = 100°44'57″ = 1.75884028343 rad

Height: ha = 13.75443483584
Height: hb = 8.84220810876
Height: hc = 6.87771741792

Median: ma = 15.48438625672
Median: mb = 12.39895116934
Median: mc = 7.58328754441

Inradius: r = 3.01992472006
Circumradius: R = 9.16107393325

Vertex coordinates: A[18; 0] B[0; 0] C[5.80655555556; 6.87771741792]
Centroid: CG[7.93551851852; 2.29223913931]
Coordinates of the circumscribed circle: U[9; -1.70985505898]
Coordinates of the inscribed circle: I[6.5; 3.01992472006]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 150.5798757281° = 150°34'44″ = 0.51334975555 rad
∠ B' = β' = 130.177030381° = 130°10'13″ = 0.87696922638 rad
∠ C' = γ' = 79.25109389095° = 79°15'3″ = 1.75884028343 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.