# 13 13 16 triangle

### Acute isosceles triangle.

Sides: a = 13   b = 13   c = 16

Area: T = 81.97656061277
Perimeter: p = 42
Semiperimeter: s = 21

Angle ∠ A = α = 52.02201275551° = 52°1'12″ = 0.90879225031 rad
Angle ∠ B = β = 52.02201275551° = 52°1'12″ = 0.90879225031 rad
Angle ∠ C = γ = 75.96597448897° = 75°57'35″ = 1.32657476473 rad

Height: ha = 12.6121631712
Height: hb = 12.6121631712
Height: hc = 10.2476950766

Median: ma = 13.04879883507
Median: mb = 13.04879883507
Median: mc = 10.2476950766

Inradius: r = 3.90436002918
Circumradius: R = 8.24663556164

Vertex coordinates: A[16; 0] B[0; 0] C[8; 10.2476950766]
Centroid: CG[8; 3.41656502553]
Coordinates of the circumscribed circle: U[8; 2.00105951495]
Coordinates of the inscribed circle: I[8; 3.90436002918]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 127.9879872445° = 127°58'48″ = 0.90879225031 rad
∠ B' = β' = 127.9879872445° = 127°58'48″ = 0.90879225031 rad
∠ C' = γ' = 104.044025511° = 104°2'25″ = 1.32657476473 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.