# 7 25 30 triangle

### Obtuse scalene triangle.

Sides: a = 7   b = 25   c = 30

Area: T = 66.8133172354
Perimeter: p = 62
Semiperimeter: s = 31

Angle ∠ A = α = 10.26330958986° = 10°15'47″ = 0.17991248149 rad
Angle ∠ B = β = 39.51876527972° = 39°31'4″ = 0.6989713154 rad
Angle ∠ C = γ = 130.2199251304° = 130°13'9″ = 2.27327546847 rad

Height: ha = 19.08994778154
Height: hb = 5.34550537883
Height: hc = 4.45442114903

Median: ma = 27.39106918496
Median: mb = 17.84395627749
Median: mc = 10.58330052443

Inradius: r = 2.15552636243
Circumradius: R = 19.64443299092

Vertex coordinates: A[30; 0] B[0; 0] C[5.4; 4.45442114903]
Centroid: CG[11.8; 1.48547371634]
Coordinates of the circumscribed circle: U[15; -12.68546244556]
Coordinates of the inscribed circle: I[6; 2.15552636243]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 169.7376904101° = 169°44'13″ = 0.17991248149 rad
∠ B' = β' = 140.4822347203° = 140°28'56″ = 0.6989713154 rad
∠ C' = γ' = 49.78107486958° = 49°46'51″ = 2.27327546847 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    