# 10 10 13 triangle

### Acute isosceles triangle.

Sides: a = 10   b = 10   c = 13

Area: T = 49.39657234991
Perimeter: p = 33
Semiperimeter: s = 16.5

Angle ∠ A = α = 49.45883981265° = 49°27'30″ = 0.86332118901 rad
Angle ∠ B = β = 49.45883981265° = 49°27'30″ = 0.86332118901 rad
Angle ∠ C = γ = 81.0833203747° = 81°5' = 1.41551688735 rad

Height: ha = 9.87991446998
Height: hb = 9.87991446998
Height: hc = 7.59993420768

Median: ma = 10.46442247682
Median: mb = 10.46442247682
Median: mc = 7.59993420768

Inradius: r = 2.99436802121
Circumradius: R = 6.58795169496

Vertex coordinates: A[13; 0] B[0; 0] C[6.5; 7.59993420768]
Centroid: CG[6.5; 2.53331140256]
Coordinates of the circumscribed circle: U[6.5; 1.02198251272]
Coordinates of the inscribed circle: I[6.5; 2.99436802121]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 130.5421601874° = 130°32'30″ = 0.86332118901 rad
∠ B' = β' = 130.5421601874° = 130°32'30″ = 0.86332118901 rad
∠ C' = γ' = 98.9176796253° = 98°55' = 1.41551688735 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.