# 21 26 29 triangle

### Acute scalene triangle.

Sides: a = 21   b = 26   c = 29

Area: T = 264.1366328437
Perimeter: p = 76
Semiperimeter: s = 38

Angle ∠ A = α = 44.47773191989° = 44°28'38″ = 0.77662756625 rad
Angle ∠ B = β = 60.1632821003° = 60°9'46″ = 1.05500393138 rad
Angle ∠ C = γ = 75.36598597981° = 75°21'35″ = 1.31552776773 rad

Height: ha = 25.15658408035
Height: hb = 20.31881791105
Height: hc = 18.21662985129

Median: ma = 25.46107541129
Median: mb = 21.72655609824
Median: mc = 18.66114576065

Inradius: r = 6.95109560115
Circumradius: R = 14.98765791784

Vertex coordinates: A[29; 0] B[0; 0] C[10.44882758621; 18.21662985129]
Centroid: CG[13.14994252874; 6.07220995043]
Coordinates of the circumscribed circle: U[14.5; 3.78878167154]
Coordinates of the inscribed circle: I[12; 6.95109560115]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 135.5232680801° = 135°31'22″ = 0.77662756625 rad
∠ B' = β' = 119.8377178997° = 119°50'14″ = 1.05500393138 rad
∠ C' = γ' = 104.6440140202° = 104°38'25″ = 1.31552776773 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.