# 7 28 30 triangle

### Obtuse scalene triangle.

Sides: a = 7   b = 28   c = 30

Area: T = 96.55879489219
Perimeter: p = 65
Semiperimeter: s = 32.5

Angle ∠ A = α = 13.2911177243° = 13°17'28″ = 0.23219748044 rad
Angle ∠ B = β = 66.86876036007° = 66°52'3″ = 1.16770598458 rad
Angle ∠ C = γ = 99.84112191563° = 99°50'28″ = 1.74325580035 rad

Height: ha = 27.58879854063
Height: hb = 6.89769963516
Height: hc = 6.43771965948

Median: ma = 28.80553814417
Median: mb = 16.68883192683
Median: mc = 13.83883525031

Inradius: r = 2.9711013813
Circumradius: R = 15.22440184927

Vertex coordinates: A[30; 0] B[0; 0] C[2.75; 6.43771965948]
Centroid: CG[10.91766666667; 2.14657321983]
Coordinates of the circumscribed circle: U[15; -2.60220643852]
Coordinates of the inscribed circle: I[4.5; 2.9711013813]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 166.7098822757° = 166°42'32″ = 0.23219748044 rad
∠ B' = β' = 113.1322396399° = 113°7'57″ = 1.16770598458 rad
∠ C' = γ' = 80.15987808437° = 80°9'32″ = 1.74325580035 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.