# 2 6 7 triangle

### Obtuse scalene triangle.

Sides: a = 2   b = 6   c = 7

Area: T = 5.56221488653
Perimeter: p = 15
Semiperimeter: s = 7.5

Angle ∠ A = α = 15.35988855808° = 15°21'32″ = 0.26880631228 rad
Angle ∠ B = β = 52.61768015821° = 52°37' = 0.91883364295 rad
Angle ∠ C = γ = 112.0244312837° = 112°1'28″ = 1.95551931013 rad

Height: ha = 5.56221488653
Height: hb = 1.85440496218
Height: hc = 1.58991853901

Median: ma = 6.44220493634
Median: mb = 4.18333001327
Median: mc = 2.78438821814

Inradius: r = 0.74216198487
Circumradius: R = 3.77655192298

Vertex coordinates: A[7; 0] B[0; 0] C[1.21442857143; 1.58991853901]
Centroid: CG[2.73880952381; 0.53297284634]
Coordinates of the circumscribed circle: U[3.5; -1.41658197112]
Coordinates of the inscribed circle: I[1.5; 0.74216198487]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 164.6411114419° = 164°38'28″ = 0.26880631228 rad
∠ B' = β' = 127.3833198418° = 127°23' = 0.91883364295 rad
∠ C' = γ' = 67.9765687163° = 67°58'32″ = 1.95551931013 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.