# 9 20 24 triangle

### Obtuse scalene triangle.

Sides: a = 9   b = 20   c = 24

Area: T = 86.81097776751
Perimeter: p = 53
Semiperimeter: s = 26.5

Angle ∠ A = α = 21.20550908133° = 21°12'18″ = 0.37700986529 rad
Angle ∠ B = β = 53.4943968335° = 53°29'38″ = 0.93436458774 rad
Angle ∠ C = γ = 105.3010940852° = 105°18'3″ = 1.83878481233 rad

Height: ha = 19.29110617056
Height: hb = 8.68109777675
Height: hc = 7.23441481396

Median: ma = 21.62875287539
Median: mb = 15.11662164578
Median: mc = 9.82334413522

Inradius: r = 3.2765840667
Circumradius: R = 12.44109948847

Vertex coordinates: A[24; 0] B[0; 0] C[5.35441666667; 7.23441481396]
Centroid: CG[9.78547222222; 2.41113827132]
Coordinates of the circumscribed circle: U[12; -3.28330403168]
Coordinates of the inscribed circle: I[6.5; 3.2765840667]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 158.7954909187° = 158°47'42″ = 0.37700986529 rad
∠ B' = β' = 126.5066031665° = 126°30'22″ = 0.93436458774 rad
∠ C' = γ' = 74.69990591483° = 74°41'57″ = 1.83878481233 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.