# 19 25 25 triangle

### Acute isosceles triangle.

Sides: a = 19   b = 25   c = 25

Area: T = 219.6844290517
Perimeter: p = 69
Semiperimeter: s = 34.5

Angle ∠ A = α = 44.66773653156° = 44°40'3″ = 0.78795925929 rad
Angle ∠ B = β = 67.66663173422° = 67°39'59″ = 1.18110000303 rad
Angle ∠ C = γ = 67.66663173422° = 67°39'59″ = 1.18110000303 rad

Height: ha = 23.12546621597
Height: hb = 17.57547432414
Height: hc = 17.57547432414

Median: ma = 23.12546621597
Median: mb = 18.35107493035
Median: mc = 18.35107493035

Inradius: r = 6.36876605947
Circumradius: R = 13.51437109395

Vertex coordinates: A[25; 0] B[0; 0] C[7.22; 17.57547432414]
Centroid: CG[10.74; 5.85882477471]
Coordinates of the circumscribed circle: U[12.5; 5.1355210157]
Coordinates of the inscribed circle: I[9.5; 6.36876605947]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 135.3332634684° = 135°19'57″ = 0.78795925929 rad
∠ B' = β' = 112.3343682658° = 112°20'1″ = 1.18110000303 rad
∠ C' = γ' = 112.3343682658° = 112°20'1″ = 1.18110000303 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.