# 7 20 25 triangle

### Obtuse scalene triangle.

Sides: a = 7   b = 20   c = 25

Area: T = 54.44326303553
Perimeter: p = 52
Semiperimeter: s = 26

Angle ∠ A = α = 12.57881186558° = 12°34'41″ = 0.22195295842 rad
Angle ∠ B = β = 38.47770777501° = 38°28'37″ = 0.67215516933 rad
Angle ∠ C = γ = 128.9454803594° = 128°56'41″ = 2.25105113761 rad

Height: ha = 15.55550372444
Height: hb = 5.44442630355
Height: hc = 4.35554104284

Median: ma = 22.36662692463
Median: mb = 15.39548043183
Median: mc = 8.26113558209

Inradius: r = 2.09439473214
Circumradius: R = 16.07219640894

Vertex coordinates: A[25; 0] B[0; 0] C[5.48; 4.35554104284]
Centroid: CG[10.16; 1.45218034761]
Coordinates of the circumscribed circle: U[12.5; -10.10223774276]
Coordinates of the inscribed circle: I[6; 2.09439473214]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 167.4221881344° = 167°25'19″ = 0.22195295842 rad
∠ B' = β' = 141.523292225° = 141°31'23″ = 0.67215516933 rad
∠ C' = γ' = 51.05551964059° = 51°3'19″ = 2.25105113761 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.