# 10 17 18 triangle

### Acute scalene triangle.

Sides: a = 10   b = 17   c = 18

Area: T = 83.43222329798
Perimeter: p = 45
Semiperimeter: s = 22.5

Angle ∠ A = α = 33.04657624726° = 33°2'45″ = 0.5776757359 rad
Angle ∠ B = β = 67.9765687163° = 67°58'32″ = 1.18663995523 rad
Angle ∠ C = γ = 78.97985503645° = 78°58'43″ = 1.37884357423 rad

Height: ha = 16.6866446596
Height: hb = 9.81655568212
Height: hc = 9.27702481089

Median: ma = 16.77879617356
Median: mb = 11.82215904175
Median: mc = 10.65436378763

Inradius: r = 3.70880992435
Circumradius: R = 9.16991181295

Vertex coordinates: A[18; 0] B[0; 0] C[3.75; 9.27702481089]
Centroid: CG[7.25; 3.0990082703]
Coordinates of the circumscribed circle: U[9; 1.75329196424]
Coordinates of the inscribed circle: I[5.5; 3.70880992435]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 146.9544237527° = 146°57'15″ = 0.5776757359 rad
∠ B' = β' = 112.0244312837° = 112°1'28″ = 1.18663995523 rad
∠ C' = γ' = 101.0211449636° = 101°1'17″ = 1.37884357423 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.