# 20 21 27 triangle

### Acute scalene triangle.

Sides: a = 20   b = 21   c = 27

Area: T = 208.1254962463
Perimeter: p = 68
Semiperimeter: s = 34

Angle ∠ A = α = 47.23334876223° = 47°14'1″ = 0.82443798762 rad
Angle ∠ B = β = 50.42987680384° = 50°25'44″ = 0.888014804 rad
Angle ∠ C = γ = 82.33877443392° = 82°20'16″ = 1.43770647374 rad

Height: ha = 20.81224962462
Height: hb = 19.82114249964
Height: hc = 15.41766638861

Median: ma = 22.02327155455
Median: mb = 21.31331414859
Median: mc = 15.43553490404

Inradius: r = 6.12113224254
Circumradius: R = 13.62216240784

Vertex coordinates: A[27; 0] B[0; 0] C[12.74107407407; 15.41766638861]
Centroid: CG[13.24769135802; 5.1398887962]
Coordinates of the circumscribed circle: U[13.5; 1.81662165438]
Coordinates of the inscribed circle: I[13; 6.12113224254]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 132.7676512378° = 132°45'59″ = 0.82443798762 rad
∠ B' = β' = 129.5711231962° = 129°34'16″ = 0.888014804 rad
∠ C' = γ' = 97.66222556608° = 97°39'44″ = 1.43770647374 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.