# 80 80.5 66 triangle

### Acute scalene triangle.

Sides: a = 80   b = 80.5   c = 66

Area: T = 2413.912230601
Perimeter: p = 226.5
Semiperimeter: s = 113.25

Angle ∠ A = α = 65.3243770709° = 65°19'26″ = 1.14401148787 rad
Angle ∠ B = β = 66.11551036176° = 66°6'54″ = 1.15439262434 rad
Angle ∠ C = γ = 48.56111256734° = 48°33'40″ = 0.84875515315 rad

Height: ha = 60.34878076502
Height: hb = 59.97329765468
Height: hc = 73.14988577578

Median: ma = 61.79109783059
Median: mb = 61.3022018727
Median: mc = 73.15113841291

Inradius: r = 21.31548989493
Circumradius: R = 44.02198261285

Vertex coordinates: A[66; 0] B[0; 0] C[32.39220454545; 73.14988577578]
Centroid: CG[32.79773484848; 24.38329525859]
Coordinates of the circumscribed circle: U[33; 29.1333230037]
Coordinates of the inscribed circle: I[32.75; 21.31548989493]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 114.6766229291° = 114°40'34″ = 1.14401148787 rad
∠ B' = β' = 113.8854896382° = 113°53'6″ = 1.15439262434 rad
∠ C' = γ' = 131.4398874327° = 131°26'20″ = 0.84875515315 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.