# 12 15 22 triangle

### Obtuse scalene triangle.

Sides: a = 12   b = 15   c = 22

Area: T = 85.28444505171
Perimeter: p = 49
Semiperimeter: s = 24.5

Angle ∠ A = α = 31.12328957773° = 31°7'22″ = 0.54331970041 rad
Angle ∠ B = β = 40.2487773648° = 40°14'52″ = 0.70224561668 rad
Angle ∠ C = γ = 108.6299330575° = 108°37'46″ = 1.89659394828 rad

Height: ha = 14.21440750862
Height: hb = 11.37112600689
Height: hc = 7.75331318652

Median: ma = 17.84765682976
Median: mb = 16.0554594358
Median: mc = 7.96986887253

Inradius: r = 3.48109979803
Circumradius: R = 11.60882122122

Vertex coordinates: A[22; 0] B[0; 0] C[9.15990909091; 7.75331318652]
Centroid: CG[10.38663636364; 2.58443772884]
Coordinates of the circumscribed circle: U[11; -3.70881789011]
Coordinates of the inscribed circle: I[9.5; 3.48109979803]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 148.8777104223° = 148°52'38″ = 0.54331970041 rad
∠ B' = β' = 139.7522226352° = 139°45'8″ = 0.70224561668 rad
∠ C' = γ' = 71.37106694253° = 71°22'14″ = 1.89659394828 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.