# 21 27 29 triangle

### Acute scalene triangle.

Sides: a = 21   b = 27   c = 29

Area: T = 271.306644574
Perimeter: p = 77
Semiperimeter: s = 38.5

Angle ∠ A = α = 43.86774365388° = 43°52'3″ = 0.7665631202 rad
Angle ∠ B = β = 62.99879108049° = 62°59'52″ = 1.10995209654 rad
Angle ∠ C = γ = 73.13546526563° = 73°8'5″ = 1.27664404862 rad

Height: ha = 25.83987091181
Height: hb = 20.09767737585
Height: hc = 18.71107893614

Median: ma = 25.97659504157
Median: mb = 21.41884499906
Median: mc = 19.35884606826

Inradius: r = 7.04769206686
Circumradius: R = 15.15216857213

Vertex coordinates: A[29; 0] B[0; 0] C[9.53444827586; 18.71107893614]
Centroid: CG[12.84548275862; 6.23769297871]
Coordinates of the circumscribed circle: U[14.5; 4.39658594376]
Coordinates of the inscribed circle: I[11.5; 7.04769206686]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 136.1332563461° = 136°7'57″ = 0.7665631202 rad
∠ B' = β' = 117.0022089195° = 117°8″ = 1.10995209654 rad
∠ C' = γ' = 106.8655347344° = 106°51'55″ = 1.27664404862 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.