# 9 18 24 triangle

### Obtuse scalene triangle.

Sides: a = 9   b = 18   c = 24

Area: T = 68.87999818314
Perimeter: p = 51
Semiperimeter: s = 25.5

Angle ∠ A = α = 18.57333497187° = 18°34'24″ = 0.32441661057 rad
Angle ∠ B = β = 39.57112194572° = 39°34'16″ = 0.69106480686 rad
Angle ∠ C = γ = 121.8555430824° = 121°51'20″ = 2.12767784793 rad

Height: ha = 15.28988848514
Height: hb = 7.64444424257
Height: hc = 5.73333318193

Median: ma = 20.73304124416
Median: mb = 15.73221327226
Median: mc = 7.64985292704

Inradius: r = 2.69880385032
Circumradius: R = 14.12879107076

Vertex coordinates: A[24; 0] B[0; 0] C[6.93875; 5.73333318193]
Centroid: CG[10.31325; 1.91111106064]
Coordinates of the circumscribed circle: U[12; -7.45663973179]
Coordinates of the inscribed circle: I[7.5; 2.69880385032]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 161.4276650281° = 161°25'36″ = 0.32441661057 rad
∠ B' = β' = 140.4298780543° = 140°25'44″ = 0.69106480686 rad
∠ C' = γ' = 58.1454569176° = 58°8'40″ = 2.12767784793 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.