# 20 24 26 triangle

### Acute scalene triangle.

Sides: a = 20   b = 24   c = 26

Area: T = 227.9880262304
Perimeter: p = 70
Semiperimeter: s = 35

Angle ∠ A = α = 46.94656106092° = 46°56'44″ = 0.81993554745 rad
Angle ∠ B = β = 61.26443462551° = 61°15'52″ = 1.06992645562 rad
Angle ∠ C = γ = 71.79900431357° = 71°47'24″ = 1.25329726229 rad

Height: ha = 22.79880262304
Height: hb = 18.9988355192
Height: hc = 17.53769432541

Median: ma = 22.93546898824
Median: mb = 19.84994332413
Median: mc = 17.86105710995

Vertex coordinates: A[26; 0] B[0; 0] C[9.61553846154; 17.53769432541]
Centroid: CG[11.87217948718; 5.84656477514]
Coordinates of the circumscribed circle: U[13; 4.27766860172]
Coordinates of the inscribed circle: I[11; 6.51437217801]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 133.0544389391° = 133°3'16″ = 0.81993554745 rad
∠ B' = β' = 118.7365653745° = 118°44'8″ = 1.06992645562 rad
∠ C' = γ' = 108.2109956864° = 108°12'36″ = 1.25329726229 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    