# 8 8 9 triangle

### Acute isosceles triangle.

Sides: a = 8   b = 8   c = 9

Area: T = 29.76547022495
Perimeter: p = 25
Semiperimeter: s = 12.5

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 = 7.44111755624
Height: hb = 7.44111755624
Height: hc = 6.61443782777

Median: ma = 7.51766481892
Median: mb = 7.51766481892
Median: mc = 6.61443782777

Inradius: r = 2.381117618
Circumradius: R = 4.83879452545

Vertex coordinates: A[9; 0] B[0; 0] C[4.5; 6.61443782777]
Centroid: CG[4.5; 2.20547927592]
Coordinates of the circumscribed circle: U[4.5; 1.77664330231]
Coordinates of the inscribed circle: I[4.5; 2.381117618]

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.