# 15 19 28 triangle

### Obtuse scalene triangle.

Sides: a = 15   b = 19   c = 28

Area: T = 133.6266344708
Perimeter: p = 62
Semiperimeter: s = 31

Angle ∠ A = α = 30.1565906991° = 30°9'21″ = 0.52663198659 rad
Angle ∠ B = β = 39.51876527972° = 39°31'4″ = 0.6989713154 rad
Angle ∠ C = γ = 110.3266440212° = 110°19'35″ = 1.92655596337 rad

Height: ha = 17.81768459611
Height: hb = 14.06659310219
Height: hc = 9.54547389077

Median: ma = 22.7211135535
Median: mb = 20.3533132437
Median: mc = 9.84988578018

Inradius: r = 4.31105272486
Circumradius: R = 14.9329690731

Vertex coordinates: A[28; 0] B[0; 0] C[11.57114285714; 9.54547389077]
Centroid: CG[13.19904761905; 3.18215796359]
Coordinates of the circumscribed circle: U[14; -5.1866103096]
Coordinates of the inscribed circle: I[12; 4.31105272486]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 149.8444093009° = 149°50'39″ = 0.52663198659 rad
∠ B' = β' = 140.4822347203° = 140°28'56″ = 0.6989713154 rad
∠ C' = γ' = 69.67435597882° = 69°40'25″ = 1.92655596337 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.