# 3 21 22 triangle

### Obtuse scalene triangle.

Sides: a = 3   b = 21   c = 22

Area: T = 30.33215017762
Perimeter: p = 46
Semiperimeter: s = 23

Angle ∠ A = α = 7.54550214793° = 7°32'42″ = 0.13216854669 rad
Angle ∠ B = β = 66.88001568171° = 66°48'1″ = 1.16658826773 rad
Angle ∠ C = γ = 105.6554821704° = 105°39'17″ = 1.84440245093 rad

Height: ha = 20.22110011841
Height: hb = 2.88987144549
Height: hc = 2.75774092524

Median: ma = 21.45334379529
Median: mb = 11.67326175299
Median: mc = 10.19880390272

Inradius: r = 1.31987609468
Circumradius: R = 11.42437667016

Vertex coordinates: A[22; 0] B[0; 0] C[1.18218181818; 2.75774092524]
Centroid: CG[7.72772727273; 0.91991364175]
Coordinates of the circumscribed circle: U[11; -3.08326037131]
Coordinates of the inscribed circle: I[2; 1.31987609468]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 172.4554978521° = 172°27'18″ = 0.13216854669 rad
∠ B' = β' = 113.2199843183° = 113°11'59″ = 1.16658826773 rad
∠ C' = γ' = 74.34551782964° = 74°20'43″ = 1.84440245093 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.