# 9 25 25 triangle

### Acute isosceles triangle.

Sides: a = 9   b = 25   c = 25

Area: T = 110.6622493646
Perimeter: p = 59
Semiperimeter: s = 29.5

Angle ∠ A = α = 20.7439519611° = 20°44'22″ = 0.36219729025 rad
Angle ∠ B = β = 79.63302401945° = 79°37'49″ = 1.39898098755 rad
Angle ∠ C = γ = 79.63302401945° = 79°37'49″ = 1.39898098755 rad

Height: ha = 24.59216652547
Height: hb = 8.85329994917
Height: hc = 8.85329994917

Median: ma = 24.59216652547
Median: mb = 14.02767601391
Median: mc = 14.02767601391

Inradius: r = 3.75112709711
Circumradius: R = 12.708755749

Vertex coordinates: A[25; 0] B[0; 0] C[1.62; 8.85329994917]
Centroid: CG[8.87333333333; 2.95109998306]
Coordinates of the circumscribed circle: U[12.5; 2.28773603482]
Coordinates of the inscribed circle: I[4.5; 3.75112709711]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 159.2660480389° = 159°15'38″ = 0.36219729025 rad
∠ B' = β' = 100.3769759805° = 100°22'11″ = 1.39898098755 rad
∠ C' = γ' = 100.3769759805° = 100°22'11″ = 1.39898098755 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.