# 12 28 29 triangle

### Acute scalene triangle.

Sides: a = 12   b = 28   c = 29

Area: T = 166.5866126373
Perimeter: p = 69
Semiperimeter: s = 34.5

Angle ∠ A = α = 24.22443512236° = 24°13'28″ = 0.4232794688 rad
Angle ∠ B = β = 73.214428532° = 73°12'51″ = 1.27878303383 rad
Angle ∠ C = γ = 82.56113634564° = 82°33'41″ = 1.44109676273 rad

Height: ha = 27.76443543955
Height: hb = 11.89990090267
Height: hc = 11.48986983706

Median: ma = 27.86657495862
Median: mb = 17.21991753577
Median: mc = 15.93295323221

Inradius: r = 4.82985833731
Circumradius: R = 14.62330664764

Vertex coordinates: A[29; 0] B[0; 0] C[3.46655172414; 11.48986983706]
Centroid: CG[10.82218390805; 3.83295661235]
Coordinates of the circumscribed circle: U[14.5; 1.89331648563]
Coordinates of the inscribed circle: I[6.5; 4.82985833731]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 155.7765648776° = 155°46'32″ = 0.4232794688 rad
∠ B' = β' = 106.786571468° = 106°47'9″ = 1.27878303383 rad
∠ C' = γ' = 97.43986365436° = 97°26'19″ = 1.44109676273 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.