# 17 26 28 triangle

### Acute scalene triangle.

Sides: a = 17   b = 26   c = 28

Area: T = 216.3187908413
Perimeter: p = 71
Semiperimeter: s = 35.5

Angle ∠ A = α = 36.46113196683° = 36°27'41″ = 0.63663700778 rad
Angle ∠ B = β = 65.35436112305° = 65°21'13″ = 1.1410635694 rad
Angle ∠ C = γ = 78.18550691012° = 78°11'6″ = 1.36545868817 rad

Height: ha = 25.44991656956
Height: hb = 16.64398391087
Height: hc = 15.45112791723

Median: ma = 25.64766372065
Median: mb = 19.17702895127
Median: mc = 16.92663108798

Inradius: r = 6.09334622088
Circumradius: R = 14.30330229106

Vertex coordinates: A[28; 0] B[0; 0] C[7.08992857143; 15.45112791723]
Centroid: CG[11.69664285714; 5.15504263908]
Coordinates of the circumscribed circle: U[14; 2.92985601208]
Coordinates of the inscribed circle: I[9.5; 6.09334622088]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 143.5398680332° = 143°32'19″ = 0.63663700778 rad
∠ B' = β' = 114.646638877° = 114°38'47″ = 1.1410635694 rad
∠ C' = γ' = 101.8154930899° = 101°48'54″ = 1.36545868817 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.