# 17 20 30 triangle

### Obtuse scalene triangle.

Sides: a = 17   b = 20   c = 30

Area: T = 161.6098902911
Perimeter: p = 67
Semiperimeter: s = 33.5

Angle ∠ A = α = 32.59549372923° = 32°35'42″ = 0.56988889752 rad
Angle ∠ B = β = 39.32881064337° = 39°19'41″ = 0.68664049458 rad
Angle ∠ C = γ = 108.0776956274° = 108°4'37″ = 1.88662987325 rad

Height: ha = 19.01328121071
Height: hb = 16.16108902911
Height: hc = 10.77439268607

Median: ma = 24.03664306834
Median: mb = 22.23773559579
Median: mc = 10.93216055545

Inradius: r = 4.82441463555
Circumradius: R = 15.77988336785

Vertex coordinates: A[30; 0] B[0; 0] C[13.15; 10.77439268607]
Centroid: CG[14.38333333333; 3.59113089536]
Coordinates of the circumscribed circle: U[15; -4.89660792738]
Coordinates of the inscribed circle: I[13.5; 4.82441463555]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 147.4055062708° = 147°24'18″ = 0.56988889752 rad
∠ B' = β' = 140.6721893566° = 140°40'19″ = 0.68664049458 rad
∠ C' = γ' = 71.9233043726° = 71°55'23″ = 1.88662987325 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.