# 11 14 18 triangle

### Obtuse scalene triangle.

Sides: a = 11   b = 14   c = 18

Area: T = 76.98801110677
Perimeter: p = 43
Semiperimeter: s = 21.5

Angle ∠ A = α = 37.65884620062° = 37°39'30″ = 0.65772641532 rad
Angle ∠ B = β = 51.03992490586° = 51°2'21″ = 0.89108029438 rad
Angle ∠ C = γ = 91.30222889352° = 91°18'8″ = 1.59435255565 rad

Height: ha = 13.99663838305
Height: hb = 10.9977158724
Height: hc = 8.55333456742

Median: ma = 15.15875063912
Median: mb = 13.17219398723
Median: mc = 8.80334084308

Inradius: r = 3.58804702822
Circumradius: R = 9.0022325281

Vertex coordinates: A[18; 0] B[0; 0] C[6.91766666667; 8.55333456742]
Centroid: CG[8.30655555556; 2.85111152247]
Coordinates of the circumscribed circle: U[9; -0.20545983018]
Coordinates of the inscribed circle: I[7.5; 3.58804702822]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 142.3421537994° = 142°20'30″ = 0.65772641532 rad
∠ B' = β' = 128.9610750941° = 128°57'39″ = 0.89108029438 rad
∠ C' = γ' = 88.69877110648° = 88°41'52″ = 1.59435255565 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.