# 23 26 30 triangle

### Acute scalene triangle.

Sides: a = 23   b = 26   c = 30

Area: T = 289.1144056213
Perimeter: p = 79
Semiperimeter: s = 39.5

Angle ∠ A = α = 47.84438182214° = 47°50'38″ = 0.83550321547 rad
Angle ∠ B = β = 56.93107578126° = 56°55'51″ = 0.99436291695 rad
Angle ∠ C = γ = 75.2255423966° = 75°13'32″ = 1.31329313294 rad

Height: ha = 25.14403527142
Height: hb = 22.24395427856
Height: hc = 19.27442704142

Median: ma = 25.60876160546
Median: mb = 23.35659414283
Median: mc = 19.42993592277

Inradius: r = 7.31993431953
Circumradius: R = 15.51329088455

Vertex coordinates: A[30; 0] B[0; 0] C[12.55; 19.27442704142]
Centroid: CG[14.18333333333; 6.42547568047]
Coordinates of the circumscribed circle: U[15; 3.95660511688]
Coordinates of the inscribed circle: I[13.5; 7.31993431953]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 132.1566181779° = 132°9'22″ = 0.83550321547 rad
∠ B' = β' = 123.0699242187° = 123°4'9″ = 0.99436291695 rad
∠ C' = γ' = 104.7754576034° = 104°46'28″ = 1.31329313294 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    