# 9 23 28 triangle

### Obtuse scalene triangle.

Sides: a = 9   b = 23   c = 28

Area: T = 93.9154855055
Perimeter: p = 60
Semiperimeter: s = 30

Angle ∠ A = α = 16.95774262942° = 16°57'27″ = 0.29659629215 rad
Angle ∠ B = β = 48.19896851042° = 48°11'23″ = 0.84110686706 rad
Angle ∠ C = γ = 114.8532888602° = 114°51'10″ = 2.00545610615 rad

Height: ha = 20.876996779
Height: hb = 8.16765091352
Height: hc = 6.70882039325

Median: ma = 25.22439965113
Median: mb = 17.32877234512
Median: mc = 10.44403065089

Inradius: r = 3.13304951685
Circumradius: R = 15.42988690447

Vertex coordinates: A[28; 0] B[0; 0] C[6; 6.70882039325]
Centroid: CG[11.33333333333; 2.23660679775]
Coordinates of the circumscribed circle: U[14; -6.48545971347]
Coordinates of the inscribed circle: I[7; 3.13304951685]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 163.0432573706° = 163°2'33″ = 0.29659629215 rad
∠ B' = β' = 131.8110314896° = 131°48'37″ = 0.84110686706 rad
∠ C' = γ' = 65.14771113984° = 65°8'50″ = 2.00545610615 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.