# 12 18 24 triangle

### Obtuse scalene triangle.

Sides: a = 12   b = 18   c = 24

Area: T = 104.5710550348
Perimeter: p = 54
Semiperimeter: s = 27

Angle ∠ A = α = 28.95550243719° = 28°57'18″ = 0.50553605103 rad
Angle ∠ B = β = 46.56774634422° = 46°34'3″ = 0.81327555614 rad
Angle ∠ C = γ = 104.4787512186° = 104°28'39″ = 1.82334765819 rad

Height: ha = 17.42884250579
Height: hb = 11.61989500386
Height: hc = 8.7144212529

Median: ma = 20.34769899494
Median: mb = 16.70332930885
Median: mc = 9.48768329805

Inradius: r = 3.87329833462
Circumradius: R = 12.39435467079

Vertex coordinates: A[24; 0] B[0; 0] C[8.25; 8.7144212529]
Centroid: CG[10.75; 2.90547375097]
Coordinates of the circumscribed circle: U[12; -3.0988386677]
Coordinates of the inscribed circle: I[9; 3.87329833462]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 151.0454975628° = 151°2'42″ = 0.50553605103 rad
∠ B' = β' = 133.4332536558° = 133°25'57″ = 0.81327555614 rad
∠ C' = γ' = 75.52224878141° = 75°31'21″ = 1.82334765819 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.