# 25 27 28 triangle

### Acute scalene triangle.

Sides: a = 25   b = 27   c = 28

Area: T = 305.9411170816
Perimeter: p = 80
Semiperimeter: s = 40

Angle ∠ A = α = 54.03442464357° = 54°2'3″ = 0.94330755091 rad
Angle ∠ B = β = 60.9410718932° = 60°56'27″ = 1.06436161939 rad
Angle ∠ C = γ = 65.02550346323° = 65°1'30″ = 1.13549009506 rad

Height: ha = 24.47552936652
Height: hb = 22.66223089493
Height: hc = 21.85329407725

Median: ma = 24.5
Median: mb = 22.85327897641
Median: mc = 21.93217121995

Inradius: r = 7.64985292704
Circumradius: R = 15.44441456421

Vertex coordinates: A[28; 0] B[0; 0] C[12.14328571429; 21.85329407725]
Centroid: CG[13.3810952381; 7.28443135908]
Coordinates of the circumscribed circle: U[14; 6.52108614933]
Coordinates of the inscribed circle: I[13; 7.64985292704]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 125.9665753564° = 125°57'57″ = 0.94330755091 rad
∠ B' = β' = 119.0599281068° = 119°3'33″ = 1.06436161939 rad
∠ C' = γ' = 114.9754965368° = 114°58'30″ = 1.13549009506 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.