# 18 29 30 triangle

### Acute scalene triangle.

Sides: a = 18   b = 29   c = 30

Area: T = 252.4521851845
Perimeter: p = 77
Semiperimeter: s = 38.5

Angle ∠ A = α = 35.47550991434° = 35°28'30″ = 0.61991572825 rad
Angle ∠ B = β = 69.22992530508° = 69°13'45″ = 1.20882784044 rad
Angle ∠ C = γ = 75.29656478059° = 75°17'44″ = 1.31441569666 rad

Height: ha = 28.05502057606
Height: hb = 17.4110472541
Height: hc = 16.83301234563

Median: ma = 28.09880426365
Median: mb = 20.04437022528
Median: mc = 18.90876704012

Inradius: r = 6.5577190957
Circumradius: R = 15.50879076322

Vertex coordinates: A[30; 0] B[0; 0] C[6.38333333333; 16.83301234563]
Centroid: CG[12.12877777778; 5.61100411521]
Coordinates of the circumscribed circle: U[15; 3.93663941787]
Coordinates of the inscribed circle: I[9.5; 6.5577190957]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 144.5254900857° = 144°31'30″ = 0.61991572825 rad
∠ B' = β' = 110.7710746949° = 110°46'15″ = 1.20882784044 rad
∠ C' = γ' = 104.7044352194° = 104°42'16″ = 1.31441569666 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.