# 12 23 26 triangle

### Obtuse scalene triangle.

Sides: a = 12   b = 23   c = 26

Area: T = 137.9987961941
Perimeter: p = 61
Semiperimeter: s = 30.5

Angle ∠ A = α = 27.48659860152° = 27°29'10″ = 0.48797209541 rad
Angle ∠ B = β = 62.20326223458° = 62°12'9″ = 1.08656405633 rad
Angle ∠ C = γ = 90.3111391639° = 90°18'41″ = 1.57662311362 rad

Height: ha = 232.9996603236
Height: hb = 121.9998227775
Height: hc = 10.61552278417

Median: ma = 23.80112604708
Median: mb = 16.66658333125
Median: mc = 12.94221791055

Inradius: r = 4.52545233423
Circumradius: R = 133.0001919939

Vertex coordinates: A[26; 0] B[0; 0] C[5.59661538462; 10.61552278417]
Centroid: CG[10.53220512821; 3.53884092806]
Coordinates of the circumscribed circle: U[13; -0.07106532174]
Coordinates of the inscribed circle: I[7.5; 4.52545233423]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 152.5144013985° = 152°30'50″ = 0.48797209541 rad
∠ B' = β' = 117.7977377654° = 117°47'51″ = 1.08656405633 rad
∠ C' = γ' = 89.6898608361° = 89°41'19″ = 1.57662311362 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.