# 10 11 20 triangle

### Obtuse scalene triangle.

Sides: a = 10   b = 11   c = 20

Area: T = 31.97655766172
Perimeter: p = 41
Semiperimeter: s = 20.5

Angle ∠ A = α = 16.89990937835° = 16°53'57″ = 0.29549448271 rad
Angle ∠ B = β = 18.64881553056° = 18°38'53″ = 0.32554717095 rad
Angle ∠ C = γ = 144.4532750911° = 144°27'10″ = 2.5211176117 rad

Height: ha = 6.39551153234
Height: hb = 5.81437412031
Height: hc = 3.19875576617

Median: ma = 15.34660092532
Median: mb = 14.82439670804
Median: mc = 3.24403703492

Inradius: r = 1.56597842252
Circumradius: R = 17.20106280476

Vertex coordinates: A[20; 0] B[0; 0] C[9.475; 3.19875576617]
Centroid: CG[9.825; 1.06658525539]
Coordinates of the circumscribed circle: U[10; -13.99550564569]
Coordinates of the inscribed circle: I[9.5; 1.56597842252]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 163.1010906217° = 163°6'3″ = 0.29549448271 rad
∠ B' = β' = 161.3521844694° = 161°21'7″ = 0.32554717095 rad
∠ C' = γ' = 35.54772490891° = 35°32'50″ = 2.5211176117 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.