# 20 20 27 triangle

### Acute isosceles triangle.

Sides: a = 20   b = 20   c = 27

Area: T = 199.2110786606
Perimeter: p = 67
Semiperimeter: s = 33.5

Angle ∠ A = α = 47.54658497956° = 47°32'45″ = 0.83298316246 rad
Angle ∠ B = β = 47.54658497956° = 47°32'45″ = 0.83298316246 rad
Angle ∠ C = γ = 84.90883004088° = 84°54'30″ = 1.48219294044 rad

Height: ha = 19.92110786606
Height: hb = 19.92110786606
Height: hc = 14.75663545634

Median: ma = 21.55222620623
Median: mb = 21.55222620623
Median: mc = 14.75663545634

Inradius: r = 5.94765906449
Circumradius: R = 13.55334829514

Vertex coordinates: A[27; 0] B[0; 0] C[13.5; 14.75663545634]
Centroid: CG[13.5; 4.91987848545]
Coordinates of the circumscribed circle: U[13.5; 1.20328716119]
Coordinates of the inscribed circle: I[13.5; 5.94765906449]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 132.4544150204° = 132°27'15″ = 0.83298316246 rad
∠ B' = β' = 132.4544150204° = 132°27'15″ = 0.83298316246 rad
∠ C' = γ' = 95.09216995912° = 95°5'30″ = 1.48219294044 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.