# 2 17 18 triangle

### Obtuse scalene triangle.

Sides: a = 2   b = 17   c = 18

Area: T = 15.13106807514
Perimeter: p = 37
Semiperimeter: s = 18.5

Angle ∠ A = α = 5.67554475446° = 5°40'32″ = 0.09990552462 rad
Angle ∠ B = β = 57.20328317042° = 57°12'10″ = 0.99883777547 rad
Angle ∠ C = γ = 117.1221720751° = 117°7'18″ = 2.04441596527 rad

Height: ha = 15.13106807514
Height: hb = 1.78800800884
Height: hc = 1.68111867502

Median: ma = 17.47985582929
Median: mb = 9.57986220303
Median: mc = 8.09332070281

Inradius: r = 0.81878746352
Circumradius: R = 10.11219045808

Vertex coordinates: A[18; 0] B[0; 0] C[1.08333333333; 1.68111867502]
Centroid: CG[6.36111111111; 0.56603955834]
Coordinates of the circumscribed circle: U[9; -4.6109838853]
Coordinates of the inscribed circle: I[1.5; 0.81878746352]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 174.3254552455° = 174°19'28″ = 0.09990552462 rad
∠ B' = β' = 122.7977168296° = 122°47'50″ = 0.99883777547 rad
∠ C' = γ' = 62.87882792488° = 62°52'42″ = 2.04441596527 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.