# 12 27 30 triangle

### Obtuse scalene triangle.

Sides: a = 12   b = 27   c = 30

Area: T = 161.8599313912
Perimeter: p = 69
Semiperimeter: s = 34.5

Angle ∠ A = α = 23.55664643091° = 23°33'23″ = 0.41111378623 rad
Angle ∠ B = β = 64.05655202276° = 64°3'20″ = 1.1187979732 rad
Angle ∠ C = γ = 92.38880154633° = 92°23'17″ = 1.61224750592 rad

Height: ha = 26.97765523186
Height: hb = 11.99895788083
Height: hc = 10.79106209275

Median: ma = 27.90216128566
Median: mb = 18.43223085912
Median: mc = 14.54330395722

Inradius: r = 4.69215743163
Circumradius: R = 15.01330378121

Vertex coordinates: A[30; 0] B[0; 0] C[5.25; 10.79106209275]
Centroid: CG[11.75; 3.59768736425]
Coordinates of the circumscribed circle: U[15; -0.62655432422]
Coordinates of the inscribed circle: I[7.5; 4.69215743163]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 156.4443535691° = 156°26'37″ = 0.41111378623 rad
∠ B' = β' = 115.9444479772° = 115°56'40″ = 1.1187979732 rad
∠ C' = γ' = 87.61219845367° = 87°36'43″ = 1.61224750592 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.