# 9 26 28 triangle

### Obtuse scalene triangle.

Sides: a = 9   b = 26   c = 28

Area: T = 116.8055126172
Perimeter: p = 63
Semiperimeter: s = 31.5

Angle ∠ A = α = 18.71769506574° = 18°43'1″ = 0.32766724149 rad
Angle ∠ B = β = 67.9765687163° = 67°58'32″ = 1.18663995523 rad
Angle ∠ C = γ = 93.30773621797° = 93°18'26″ = 1.62985206864 rad

Height: ha = 25.95766947048
Height: hb = 8.98550097055
Height: hc = 8.3433223298

Median: ma = 26.64111336095
Median: mb = 16.23326830807
Median: mc = 13.50992560861

Inradius: r = 3.70880992435
Circumradius: R = 14.02333571392

Vertex coordinates: A[28; 0] B[0; 0] C[3.375; 8.3433223298]
Centroid: CG[10.45883333333; 2.78110744327]
Coordinates of the circumscribed circle: U[14; -0.8099039835]
Coordinates of the inscribed circle: I[5.5; 3.70880992435]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 161.2833049343° = 161°16'59″ = 0.32766724149 rad
∠ B' = β' = 112.0244312837° = 112°1'28″ = 1.18663995523 rad
∠ C' = γ' = 86.69326378203° = 86°41'34″ = 1.62985206864 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.