# 3 28 30 triangle

### Obtuse scalene triangle.

Sides: a = 3   b = 28   c = 30

Area: T = 32.38795846175
Perimeter: p = 61
Semiperimeter: s = 30.5

Angle ∠ A = α = 4.42215624392° = 4°25'18″ = 0.07771708226 rad
Angle ∠ B = β = 46.01770368696° = 46°1'1″ = 0.80331488054 rad
Angle ∠ C = γ = 129.5611400691° = 129°33'41″ = 2.26112730256 rad

Height: ha = 21.5866389745
Height: hb = 2.31328274727
Height: hc = 2.15986389745

Median: ma = 28.97884402617
Median: mb = 16.07879351908
Median: mc = 13.09658008537

Inradius: r = 1.06216257252
Circumradius: R = 19.45767041994

Vertex coordinates: A[30; 0] B[0; 0] C[2.08333333333; 2.15986389745]
Centroid: CG[10.69444444444; 0.72195463248]
Coordinates of the circumscribed circle: U[15; -12.39220675555]
Coordinates of the inscribed circle: I[2.5; 1.06216257252]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 175.5788437561° = 175°34'42″ = 0.07771708226 rad
∠ B' = β' = 133.983296313° = 133°58'59″ = 0.80331488054 rad
∠ C' = γ' = 50.43985993088° = 50°26'19″ = 2.26112730256 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.