# 21 25 27 triangle

### Acute scalene triangle.

Sides: a = 21   b = 25   c = 27

Area: T = 248.6132524825
Perimeter: p = 73
Semiperimeter: s = 36.5

Angle ∠ A = α = 47.44551038672° = 47°26'42″ = 0.82880732764 rad
Angle ∠ B = β = 61.27554267539° = 61°16'32″ = 1.06994579474 rad
Angle ∠ C = γ = 71.27994693789° = 71°16'46″ = 1.24440614297 rad

Height: ha = 23.67773833167
Height: hb = 19.8899001986
Height: hc = 18.41657425797

Median: ma = 23.80765117142
Median: mb = 20.70662792408
Median: mc = 18.72883208003

Inradius: r = 6.811130205
Circumradius: R = 14.25441088889

Vertex coordinates: A[27; 0] B[0; 0] C[10.09325925926; 18.41657425797]
Centroid: CG[12.36441975309; 6.13985808599]
Coordinates of the circumscribed circle: U[13.5; 4.57548901862]
Coordinates of the inscribed circle: I[11.5; 6.811130205]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 132.5554896133° = 132°33'18″ = 0.82880732764 rad
∠ B' = β' = 118.7254573246° = 118°43'28″ = 1.06994579474 rad
∠ C' = γ' = 108.7210530621° = 108°43'14″ = 1.24440614297 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.