# 8 9 15 triangle

### Obtuse scalene triangle.

Sides: a = 8   b = 9   c = 15

Area: T = 29.93332590942
Perimeter: p = 32
Semiperimeter: s = 16

Angle ∠ A = α = 26.32545765375° = 26°19'28″ = 0.45994505348 rad
Angle ∠ B = β = 29.92664348666° = 29°55'35″ = 0.52223148218 rad
Angle ∠ C = γ = 123.7498988596° = 123°44'56″ = 2.1659827297 rad

Height: ha = 7.48333147735
Height: hb = 6.65218353543
Height: hc = 3.99111012126

Median: ma = 11.70546999107
Median: mb = 11.14767484048
Median: mc = 4.03111288741

Inradius: r = 1.87108286934
Circumradius: R = 9.02200669145

Vertex coordinates: A[15; 0] B[0; 0] C[6.93333333333; 3.99111012126]
Centroid: CG[7.31111111111; 1.33303670709]
Coordinates of the circumscribed circle: U[7.5; -5.01111482859]
Coordinates of the inscribed circle: I[7; 1.87108286934]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 153.6755423463° = 153°40'32″ = 0.45994505348 rad
∠ B' = β' = 150.0743565133° = 150°4'25″ = 0.52223148218 rad
∠ C' = γ' = 56.25110114041° = 56°15'4″ = 2.1659827297 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.