# 24 26 28 triangle

### Acute scalene triangle.

Sides: a = 24   b = 26   c = 28

Area: T = 289.2321740997
Perimeter: p = 78
Semiperimeter: s = 39

Angle ∠ A = α = 52.61768015821° = 52°37' = 0.91883364295 rad
Angle ∠ B = β = 59.40875112549° = 59°24'27″ = 1.03768566718 rad
Angle ∠ C = γ = 67.9765687163° = 67°58'32″ = 1.18663995523 rad

Height: ha = 24.10326450831
Height: hb = 22.24985954613
Height: hc = 20.65994100712

Median: ma = 24.20774368738
Median: mb = 22.60553091109
Median: mc = 20.73664413533

Inradius: r = 7.41661984871
Circumradius: R = 15.10220769192

Vertex coordinates: A[28; 0] B[0; 0] C[12.21442857143; 20.65994100712]
Centroid: CG[13.40547619048; 6.88664700237]
Coordinates of the circumscribed circle: U[14; 5.66332788447]
Coordinates of the inscribed circle: I[13; 7.41661984871]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 127.3833198418° = 127°23' = 0.91883364295 rad
∠ B' = β' = 120.5922488745° = 120°35'33″ = 1.03768566718 rad
∠ C' = γ' = 112.0244312837° = 112°1'28″ = 1.18663995523 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    