# 5.5 5.3 7.8 triangle

### Obtuse scalene triangle.

Sides: a = 5.5   b = 5.3   c = 7.8

Area: T = 14.56215933194
Perimeter: p = 18.6
Semiperimeter: s = 9.3

Angle ∠ A = α = 44.78875169949° = 44°47'15″ = 0.78216896354 rad
Angle ∠ B = β = 42.75547920255° = 42°45'17″ = 0.74662118919 rad
Angle ∠ C = γ = 92.45876909797° = 92°27'28″ = 1.61436911264 rad

Height: ha = 5.29551248434
Height: hb = 5.49549408753
Height: hc = 3.73437418768

Median: ma = 6.07547427929
Median: mb = 6.20766496598
Median: mc = 3.73663083385

Inradius: r = 1.56657627225
Circumradius: R = 3.90435906822

Vertex coordinates: A[7.8; 0] B[0; 0] C[4.03884615385; 3.73437418768]
Centroid: CG[3.94661538462; 1.24545806256]
Coordinates of the circumscribed circle: U[3.9; -0.16773923963]
Coordinates of the inscribed circle: I[4; 1.56657627225]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 135.2122483005° = 135°12'45″ = 0.78216896354 rad
∠ B' = β' = 137.2455207975° = 137°14'43″ = 0.74662118919 rad
∠ C' = γ' = 87.54223090203° = 87°32'32″ = 1.61436911264 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.