# 18 25 30 triangle

### Acute scalene triangle.

Sides: a = 18   b = 25   c = 30

Area: T = 224.6666280291
Perimeter: p = 73
Semiperimeter: s = 36.5

Angle ∠ A = α = 36.80661884285° = 36°48'22″ = 0.64223891732 rad
Angle ∠ B = β = 56.315479162° = 56°18'53″ = 0.98328785313 rad
Angle ∠ C = γ = 86.87990199516° = 86°52'44″ = 1.51663249491 rad

Height: ha = 24.96329200324
Height: hb = 17.97333024233
Height: hc = 14.97877520194

Median: ma = 26.10655549644
Median: mb = 21.34883020402
Median: mc = 15.79655689989

Inradius: r = 6.15552405559
Circumradius: R = 15.02222810278

Vertex coordinates: A[30; 0] B[0; 0] C[9.98333333333; 14.97877520194]
Centroid: CG[13.32877777778; 4.99325840065]
Coordinates of the circumscribed circle: U[15; 0.81878797448]
Coordinates of the inscribed circle: I[11.5; 6.15552405559]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 143.1943811572° = 143°11'38″ = 0.64223891732 rad
∠ B' = β' = 123.685520838° = 123°41'7″ = 0.98328785313 rad
∠ C' = γ' = 93.12109800484° = 93°7'16″ = 1.51663249491 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 ### 6. Inradius ### 7. Circumradius ### 8. Calculation of medians #### Look also our friend's collection of math examples and problems:

See more informations about triangles or more information about solving triangles.