# 7 16 18 triangle

### Obtuse scalene triangle.

Sides: a = 7   b = 16   c = 18

Area: T = 55.79881854544
Perimeter: p = 41
Semiperimeter: s = 20.5

Angle ∠ A = α = 22.79882480997° = 22°47'54″ = 0.3987904493 rad
Angle ∠ B = β = 62.33659955038° = 62°20'10″ = 1.0887968364 rad
Angle ∠ C = γ = 94.86657563965° = 94°51'57″ = 1.65657197965 rad

Height: ha = 15.94223387012
Height: hb = 6.97547731818
Height: hc = 6.21997983838

Median: ma = 16.66658333125
Median: mb = 11.06879718106
Median: mc = 8.45657672626

Inradius: r = 2.72218627051
Circumradius: R = 9.03325517917

Vertex coordinates: A[18; 0] B[0; 0] C[3.25; 6.21997983838]
Centroid: CG[7.08333333333; 2.06765994613]
Coordinates of the circumscribed circle: U[9; -0.76661539466]
Coordinates of the inscribed circle: I[4.5; 2.72218627051]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 157.20217519° = 157°12'6″ = 0.3987904493 rad
∠ B' = β' = 117.6644004496° = 117°39'50″ = 1.0887968364 rad
∠ C' = γ' = 85.13442436035° = 85°8'3″ = 1.65657197965 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.