# 20 20 29 triangle

### Obtuse isosceles triangle.

Sides: a = 20   b = 20   c = 29

Area: T = 199.7377171052
Perimeter: p = 69
Semiperimeter: s = 34.5

Angle ∠ A = α = 43.53111521674° = 43°31'52″ = 0.76597619325 rad
Angle ∠ B = β = 43.53111521674° = 43°31'52″ = 0.76597619325 rad
Angle ∠ C = γ = 92.93876956653° = 92°56'16″ = 1.62220687886 rad

Height: ha = 19.97437171052
Height: hb = 19.97437171052
Height: hc = 13.7754977314

Median: ma = 22.81444690931
Median: mb = 22.81444690931
Median: mc = 13.7754977314

Inradius: r = 5.78994832189
Circumradius: R = 14.51990801728

Vertex coordinates: A[29; 0] B[0; 0] C[14.5; 13.7754977314]
Centroid: CG[14.5; 4.59216591047]
Coordinates of the circumscribed circle: U[14.5; -0.74441028589]
Coordinates of the inscribed circle: I[14.5; 5.78994832189]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 136.4698847833° = 136°28'8″ = 0.76597619325 rad
∠ B' = β' = 136.4698847833° = 136°28'8″ = 0.76597619325 rad
∠ C' = γ' = 87.06223043347° = 87°3'44″ = 1.62220687886 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.