# 7 23 25 triangle

### Obtuse scalene triangle.

Sides: a = 7   b = 23   c = 25

Area: T = 79.6387852181
Perimeter: p = 55
Semiperimeter: s = 27.5

Angle ∠ A = α = 16.08113096745° = 16°4'53″ = 0.28106718019 rad
Angle ∠ B = β = 65.52656574372° = 65°31'32″ = 1.14436384668 rad
Angle ∠ C = γ = 98.39330328884° = 98°23'35″ = 1.71772823849 rad

Height: ha = 22.75436720517
Height: hb = 6.92550306244
Height: hc = 6.37110281745

Median: ma = 23.76444692766
Median: mb = 14.30990880213
Median: mc = 11.52217186218

Inradius: r = 2.89659218975
Circumradius: R = 12.63553231842

Vertex coordinates: A[25; 0] B[0; 0] C[2.9; 6.37110281745]
Centroid: CG[9.3; 2.12436760582]
Coordinates of the circumscribed circle: U[12.5; -1.84442863033]
Coordinates of the inscribed circle: I[4.5; 2.89659218975]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 163.9198690326° = 163°55'7″ = 0.28106718019 rad
∠ B' = β' = 114.4744342563° = 114°28'28″ = 1.14436384668 rad
∠ C' = γ' = 81.60769671116° = 81°36'25″ = 1.71772823849 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    