# 7 12 17 triangle

### Obtuse scalene triangle.

Sides: a = 7   b = 12   c = 17

Area: T = 34.46773758792
Perimeter: p = 36
Semiperimeter: s = 18

Angle ∠ A = α = 19.75499227956° = 19°45' = 0.34547011798 rad
Angle ∠ B = β = 35.44001726253° = 35°24'1″ = 0.61878495681 rad
Angle ∠ C = γ = 124.8549904579° = 124°51' = 2.17990419057 rad

Height: ha = 9.84878216798
Height: hb = 5.74545626465
Height: hc = 4.05549853976

Median: ma = 14.2921605928
Median: mb = 11.53325625947
Median: mc = 4.92444289009

Inradius: r = 1.91548542155
Circumradius: R = 10.35876205294

Vertex coordinates: A[17; 0] B[0; 0] C[5.70658823529; 4.05549853976]
Centroid: CG[7.5698627451; 1.35216617992]
Coordinates of the circumscribed circle: U[8.5; -5.91986403025]
Coordinates of the inscribed circle: I[6; 1.91548542155]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 160.2550077204° = 160°15' = 0.34547011798 rad
∠ B' = β' = 144.6599827375° = 144°35'59″ = 0.61878495681 rad
∠ C' = γ' = 55.1550095421° = 55°9' = 2.17990419057 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.