# 9 11 15 triangle

### Obtuse scalene triangle.

Sides: a = 9   b = 11   c = 15

Area: T = 49.16549010982
Perimeter: p = 35
Semiperimeter: s = 17.5

Angle ∠ A = α = 36.58795428375° = 36°34'46″ = 0.63884334614 rad
Angle ∠ B = β = 46.75498273458° = 46°44'59″ = 0.81659384119 rad
Angle ∠ C = γ = 96.67106298167° = 96°40'14″ = 1.68772207803 rad

Height: ha = 10.92655335774
Height: hb = 8.9399072927
Height: hc = 6.55553201464

Median: ma = 12.35992070943
Median: mb = 11.07992599031
Median: mc = 6.69895440801

Inradius: r = 2.80994229199
Circumradius: R = 7.55111186173

Vertex coordinates: A[15; 0] B[0; 0] C[6.16766666667; 6.55553201464]
Centroid: CG[7.05655555556; 2.18551067155]
Coordinates of the circumscribed circle: U[7.5; -0.87771501424]
Coordinates of the inscribed circle: I[6.5; 2.80994229199]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 143.4220457162° = 143°25'14″ = 0.63884334614 rad
∠ B' = β' = 133.2550172654° = 133°15'1″ = 0.81659384119 rad
∠ C' = γ' = 83.32993701833° = 83°19'46″ = 1.68772207803 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.