# 7 11 13 triangle

### Acute scalene triangle.

Sides: a = 7   b = 11   c = 13

Area: T = 38.49991883031
Perimeter: p = 31
Semiperimeter: s = 15.5

Angle ∠ A = α = 32.57881984923° = 32°34'42″ = 0.56985968281 rad
Angle ∠ B = β = 57.79438546387° = 57°47'38″ = 1.00986930509 rad
Angle ∠ C = γ = 89.6287946869° = 89°37'41″ = 1.56443027747 rad

Height: ha = 110.9997680866
Height: hb = 76.9998524188
Height: hc = 5.92329520466

Median: ma = 11.52217186218
Median: mb = 8.87441196746
Median: mc = 6.53883484153

Inradius: r = 2.48438186002
Circumradius: R = 6.55001370426

Vertex coordinates: A[13; 0] B[0; 0] C[3.73107692308; 5.92329520466]
Centroid: CG[5.57769230769; 1.97443173489]
Coordinates of the circumscribed circle: U[6.5; 0.04222086821]
Coordinates of the inscribed circle: I[4.5; 2.48438186002]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 147.4221801508° = 147°25'18″ = 0.56985968281 rad
∠ B' = β' = 122.2066145361° = 122°12'22″ = 1.00986930509 rad
∠ C' = γ' = 90.3722053131° = 90°22'19″ = 1.56443027747 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.