# 16 16 18 triangle

### Acute isosceles triangle.

Sides: a = 16   b = 16   c = 18

Area: T = 119.0598808998
Perimeter: p = 50
Semiperimeter: s = 25

Angle ∠ A = α = 55.77111336722° = 55°46'16″ = 0.97333899101 rad
Angle ∠ B = β = 55.77111336722° = 55°46'16″ = 0.97333899101 rad
Angle ∠ C = γ = 68.45877326556° = 68°27'28″ = 1.19548128333 rad

Height: ha = 14.88223511247
Height: hb = 14.88223511247
Height: hc = 13.22987565553

Median: ma = 15.03332963784
Median: mb = 15.03332963784
Median: mc = 13.22987565553

Inradius: r = 4.76223523599
Circumradius: R = 9.6765890509

Vertex coordinates: A[18; 0] B[0; 0] C[9; 13.22987565553]
Centroid: CG[9; 4.41095855184]
Coordinates of the circumscribed circle: U[9; 3.55328660463]
Coordinates of the inscribed circle: I[9; 4.76223523599]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 124.2298866328° = 124°13'44″ = 0.97333899101 rad
∠ B' = β' = 124.2298866328° = 124°13'44″ = 0.97333899101 rad
∠ C' = γ' = 111.5422267344° = 111°32'32″ = 1.19548128333 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.