# 20 25 30 triangle

### Acute scalene triangle.

Sides: a = 20   b = 25   c = 30

Area: T = 248.0399185412
Perimeter: p = 75
Semiperimeter: s = 37.5

Angle ∠ A = α = 41.41096221093° = 41°24'35″ = 0.72327342478 rad
Angle ∠ B = β = 55.77111336722° = 55°46'16″ = 0.97333899101 rad
Angle ∠ C = γ = 82.81992442185° = 82°49'9″ = 1.44554684956 rad

Height: ha = 24.80439185412
Height: hb = 19.8433134833
Height: hc = 16.53659456942

Median: ma = 25.73990753525
Median: mb = 22.22204860433
Median: mc = 16.95658249578

Inradius: r = 6.61443782777
Circumradius: R = 15.11985789204

Vertex coordinates: A[30; 0] B[0; 0] C[11.25; 16.53659456942]
Centroid: CG[13.75; 5.51219818981]
Coordinates of the circumscribed circle: U[15; 1.8989822365]
Coordinates of the inscribed circle: I[12.5; 6.61443782777]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 138.5990377891° = 138°35'25″ = 0.72327342478 rad
∠ B' = β' = 124.2298866328° = 124°13'44″ = 0.97333899101 rad
∠ C' = γ' = 97.18107557815° = 97°10'51″ = 1.44554684956 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.