# 12 25 25 triangle

### Acute isosceles triangle.

Sides: a = 12   b = 25   c = 25

Area: T = 145.6165933194
Perimeter: p = 62
Semiperimeter: s = 31

Angle ∠ A = α = 27.77330807253° = 27°46'23″ = 0.48547317021 rad
Angle ∠ B = β = 76.11334596374° = 76°6'48″ = 1.32884304758 rad
Angle ∠ C = γ = 76.11334596374° = 76°6'48″ = 1.32884304758 rad

Height: ha = 24.2699322199
Height: hb = 11.64992746555
Height: hc = 11.64992746555

Median: ma = 24.2699322199
Median: mb = 15.10879449297
Median: mc = 15.10879449297

Inradius: r = 4.69772881676
Circumradius: R = 12.87663381786

Vertex coordinates: A[25; 0] B[0; 0] C[2.88; 11.64992746555]
Centroid: CG[9.29333333333; 3.88330915518]
Coordinates of the circumscribed circle: U[12.5; 3.09903211629]
Coordinates of the inscribed circle: I[6; 4.69772881676]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 152.2276919275° = 152°13'37″ = 0.48547317021 rad
∠ B' = β' = 103.8876540363° = 103°53'12″ = 1.32884304758 rad
∠ C' = γ' = 103.8876540363° = 103°53'12″ = 1.32884304758 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.