# 6 12 13 triangle

### Acute scalene triangle.

Sides: a = 6   b = 12   c = 13

Area: T = 35.89548116028
Perimeter: p = 31
Semiperimeter: s = 15.5

Angle ∠ A = α = 27.39993615864° = 27°23'58″ = 0.47882090726 rad
Angle ∠ B = β = 66.98216671563° = 66°58'54″ = 1.16990506304 rad
Angle ∠ C = γ = 85.61989712574° = 85°37'8″ = 1.49443329506 rad

Height: ha = 11.96549372009
Height: hb = 5.98224686005
Height: hc = 5.52222787081

Median: ma = 12.14549578015
Median: mb = 8.15547532152
Median: mc = 6.91101374805

Inradius: r = 2.3165794297
Circumradius: R = 6.51990480059

Vertex coordinates: A[13; 0] B[0; 0] C[2.34661538462; 5.52222787081]
Centroid: CG[5.11553846154; 1.84107595694]
Coordinates of the circumscribed circle: U[6.5; 0.49879828338]
Coordinates of the inscribed circle: I[3.5; 2.3165794297]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 152.6010638414° = 152°36'2″ = 0.47882090726 rad
∠ B' = β' = 113.0188332844° = 113°1'6″ = 1.16990506304 rad
∠ C' = γ' = 94.38110287426° = 94°22'52″ = 1.49443329506 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.