# 8 14 21 triangle

### Obtuse scalene triangle.

Sides: a = 8   b = 14   c = 21

Area: T = 32.99114761719
Perimeter: p = 43
Semiperimeter: s = 21.5

Angle ∠ A = α = 12.96994688473° = 12°58'10″ = 0.22663599336 rad
Angle ∠ B = β = 23.12660741872° = 23°7'34″ = 0.40436261376 rad
Angle ∠ C = γ = 143.9044456966° = 143°54'16″ = 2.51216065823 rad

Height: ha = 8.2487869043
Height: hb = 4.71330680246
Height: hc = 3.14220453497

Median: ma = 17.39325271309
Median: mb = 14.26553426177
Median: mc = 4.44440972087

Inradius: r = 1.53444872638
Circumradius: R = 17.82327854048

Vertex coordinates: A[21; 0] B[0; 0] C[7.35771428571; 3.14220453497]
Centroid: CG[9.45223809524; 1.04773484499]
Coordinates of the circumscribed circle: U[10.5; -14.40114471352]
Coordinates of the inscribed circle: I[7.5; 1.53444872638]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 167.0310531153° = 167°1'50″ = 0.22663599336 rad
∠ B' = β' = 156.8743925813° = 156°52'26″ = 0.40436261376 rad
∠ C' = γ' = 36.09655430345° = 36°5'44″ = 2.51216065823 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.