# 9 10 10 triangle

### Acute isosceles triangle.

Sides: a = 9   b = 10   c = 10

Area: T = 40.18662849739
Perimeter: p = 29
Semiperimeter: s = 14.5

Angle ∠ A = α = 53.48773679008° = 53°29'15″ = 0.93435306781 rad
Angle ∠ B = β = 63.25663160496° = 63°15'23″ = 1.10440309877 rad
Angle ∠ C = γ = 63.25663160496° = 63°15'23″ = 1.10440309877 rad

Height: ha = 8.93302855497
Height: hb = 8.03772569948
Height: hc = 8.03772569948

Median: ma = 8.93302855497
Median: mb = 8.09332070281
Median: mc = 8.09332070281

Inradius: r = 2.77114679292
Circumradius: R = 5.59989251096

Vertex coordinates: A[10; 0] B[0; 0] C[4.05; 8.03772569948]
Centroid: CG[4.68333333333; 2.67990856649]
Coordinates of the circumscribed circle: U[5; 2.52195162993]
Coordinates of the inscribed circle: I[4.5; 2.77114679292]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 126.5132632099° = 126°30'45″ = 0.93435306781 rad
∠ B' = β' = 116.744368395° = 116°44'37″ = 1.10440309877 rad
∠ C' = γ' = 116.744368395° = 116°44'37″ = 1.10440309877 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.