# 9 25 30 triangle

### Obtuse scalene triangle.

Sides: a = 9   b = 25   c = 30

Area: T = 101.5098620324
Perimeter: p = 64
Semiperimeter: s = 32

Angle ∠ A = α = 15.70553094058° = 15°42'19″ = 0.27441093592 rad
Angle ∠ B = β = 48.75765958652° = 48°45'24″ = 0.85109631299 rad
Angle ∠ C = γ = 115.5388094729° = 115°32'17″ = 2.01765201645 rad

Height: ha = 22.5577471183
Height: hb = 8.12106896259
Height: hc = 6.76772413549

Median: ma = 27.24442654517
Median: mb = 18.28325052988
Median: mc = 11.3143708499

Inradius: r = 3.17221443851
Circumradius: R = 16.62442038816

Vertex coordinates: A[30; 0] B[0; 0] C[5.93333333333; 6.76772413549]
Centroid: CG[11.97877777778; 2.25657471183]
Coordinates of the circumscribed circle: U[15; -7.16768790067]
Coordinates of the inscribed circle: I[7; 3.17221443851]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 164.2954690594° = 164°17'41″ = 0.27441093592 rad
∠ B' = β' = 131.2433404135° = 131°14'36″ = 0.85109631299 rad
∠ C' = γ' = 64.4621905271° = 64°27'43″ = 2.01765201645 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    