# 13 16 20 triangle

### Acute scalene triangle.

Sides: a = 13   b = 16   c = 20

Area: T = 103.812202965
Perimeter: p = 49
Semiperimeter: s = 24.5

Angle ∠ A = α = 40.4533084335° = 40°27'11″ = 0.70660395142 rad
Angle ∠ B = β = 52.99222476015° = 52°59'32″ = 0.92548891987 rad
Angle ∠ C = γ = 86.55546680635° = 86°33'17″ = 1.51106639407 rad

Height: ha = 15.97110814846
Height: hb = 12.97765037062
Height: hc = 10.3811202965

Median: ma = 16.90441415044
Median: mb = 14.84992424049
Median: mc = 10.60766017178

Inradius: r = 4.23772257
Circumradius: R = 10.01881067985

Vertex coordinates: A[20; 0] B[0; 0] C[7.825; 10.3811202965]
Centroid: CG[9.275; 3.46604009883]
Coordinates of the circumscribed circle: U[10; 0.60220496874]
Coordinates of the inscribed circle: I[8.5; 4.23772257]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 139.5476915665° = 139°32'49″ = 0.70660395142 rad
∠ B' = β' = 127.0087752398° = 127°28″ = 0.92548891987 rad
∠ C' = γ' = 93.44553319365° = 93°26'43″ = 1.51106639407 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.