# 15 15 17 triangle

### Acute isosceles triangle.

Sides: a = 15   b = 15   c = 17

Area: T = 105.0533260302
Perimeter: p = 47
Semiperimeter: s = 23.5

Angle ∠ A = α = 55.48218921589° = 55°28'55″ = 0.96883416934 rad
Angle ∠ B = β = 55.48218921589° = 55°28'55″ = 0.96883416934 rad
Angle ∠ C = γ = 69.03662156821° = 69°2'10″ = 1.20549092668 rad

Height: ha = 14.00771013735
Height: hb = 14.00771013735
Height: hc = 12.35992070943

Median: ma = 14.16986273153
Median: mb = 14.16986273153
Median: mc = 12.35992070943

Inradius: r = 4.47703515022
Circumradius: R = 9.10325256832

Vertex coordinates: A[17; 0] B[0; 0] C[8.5; 12.35992070943]
Centroid: CG[8.5; 4.12197356981]
Coordinates of the circumscribed circle: U[8.5; 3.25766814111]
Coordinates of the inscribed circle: I[8.5; 4.47703515022]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 124.5188107841° = 124°31'5″ = 0.96883416934 rad
∠ B' = β' = 124.5188107841° = 124°31'5″ = 0.96883416934 rad
∠ C' = γ' = 110.9643784318° = 110°57'50″ = 1.20549092668 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.