# 9 13 16 triangle

### Obtuse scalene triangle.

Sides: a = 9   b = 13   c = 16

Area: T = 58.48107660689
Perimeter: p = 38
Semiperimeter: s = 19

Angle ∠ A = α = 34.21660511313° = 34°12'58″ = 0.59771827493 rad
Angle ∠ B = β = 54.31546652873° = 54°18'53″ = 0.94879697414 rad
Angle ∠ C = γ = 91.46992835814° = 91°28'9″ = 1.59664401629 rad

Height: ha = 12.99657257931
Height: hb = 8.99770409337
Height: hc = 7.31100957586

Median: ma = 13.86554246239
Median: mb = 11.23661025271
Median: mc = 7.81102496759

Inradius: r = 3.07879350563
Circumradius: R = 8.00326311463

Vertex coordinates: A[16; 0] B[0; 0] C[5.25; 7.31100957586]
Centroid: CG[7.08333333333; 2.43766985862]
Coordinates of the circumscribed circle: U[8; -0.20551956704]
Coordinates of the inscribed circle: I[6; 3.07879350563]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 145.7843948869° = 145°47'2″ = 0.59771827493 rad
∠ B' = β' = 125.6855334713° = 125°41'7″ = 0.94879697414 rad
∠ C' = γ' = 88.53107164186° = 88°31'51″ = 1.59664401629 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.