# Triangle calculator SSS - result

Please enter the triangle sides:

### Obtuse scalene triangle.

Sides: a = 10   b = 17   c = 20

Area: T = 84.9565503059
Perimeter: p = 47
Semiperimeter: s = 23.5

Angle ∠ A = α = 29.98326844873° = 29°58'58″ = 0.52332965629 rad
Angle ∠ B = β = 58.16333049964° = 58°9'48″ = 1.0155141176 rad
Angle ∠ C = γ = 91.85440105163° = 91°51'14″ = 1.60331549147 rad

Height: ha = 16.99111006118
Height: hb = 9.99547650658
Height: hc = 8.49655503059

Median: ma = 17.87545629317
Median: mb = 13.3322291626
Median: mc = 9.72111110476

Inradius: r = 3.61551277897
Circumradius: R = 10.00552376761

Vertex coordinates: A[20; 0] B[0; 0] C[5.275; 8.49655503059]
Centroid: CG[8.425; 2.8321850102]
Coordinates of the circumscribed circle: U[10; -0.3243698866]
Coordinates of the inscribed circle: I[6.5; 3.61551277897]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 150.0177315513° = 150°1'2″ = 0.52332965629 rad
∠ B' = β' = 121.8376695004° = 121°50'12″ = 1.0155141176 rad
∠ C' = γ' = 88.14659894837° = 88°8'46″ = 1.60331549147 rad

# How did we calculate this triangle?

### 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    