# 9 9 10 triangle

### Acute isosceles triangle.

Sides: a = 9   b = 9   c = 10

Area: T = 37.41765738677
Perimeter: p = 28
Semiperimeter: s = 14

Angle ∠ A = α = 56.25110114041° = 56°15'4″ = 0.98217653566 rad
Angle ∠ B = β = 56.25110114041° = 56°15'4″ = 0.98217653566 rad
Angle ∠ C = γ = 67.49879771918° = 67°29'53″ = 1.17880619404 rad

Height: ha = 8.31547941928
Height: hb = 8.31547941928
Height: hc = 7.48333147735

Median: ma = 8.38215273071
Median: mb = 8.38215273071
Median: mc = 7.48333147735

Inradius: r = 2.67326124191
Circumradius: R = 5.41220401487

Vertex coordinates: A[10; 0] B[0; 0] C[5; 7.48333147735]
Centroid: CG[5; 2.49444382578]
Coordinates of the circumscribed circle: U[5; 2.07112746248]
Coordinates of the inscribed circle: I[5; 2.67326124191]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 123.7498988596° = 123°44'56″ = 0.98217653566 rad
∠ B' = β' = 123.7498988596° = 123°44'56″ = 0.98217653566 rad
∠ C' = γ' = 112.5022022808° = 112°30'7″ = 1.17880619404 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.