# 15 22 25 triangle

### Acute scalene triangle.

Sides: a = 15   b = 22   c = 25

Area: T = 163.6588180364
Perimeter: p = 62
Semiperimeter: s = 31

Angle ∠ A = α = 36.521123386° = 36°31'16″ = 0.63774157777 rad
Angle ∠ B = β = 60.79107880662° = 60°47'27″ = 1.06109994066 rad
Angle ∠ C = γ = 82.68879780737° = 82°41'17″ = 1.44331774692 rad

Height: ha = 21.82110907152
Height: hb = 14.87880163967
Height: hc = 13.09326544291

Median: ma = 22.32215142855
Median: mb = 17.43655957742
Median: mc = 14.08801278403

Inradius: r = 5.27992961408
Circumradius: R = 12.60224864471

Vertex coordinates: A[25; 0] B[0; 0] C[7.32; 13.09326544291]
Centroid: CG[10.77333333333; 4.3644218143]
Coordinates of the circumscribed circle: U[12.5; 1.60439528205]
Coordinates of the inscribed circle: I[9; 5.27992961408]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 143.479876614° = 143°28'44″ = 0.63774157777 rad
∠ B' = β' = 119.2099211934° = 119°12'33″ = 1.06109994066 rad
∠ C' = γ' = 97.31220219263° = 97°18'43″ = 1.44331774692 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    