# 21 22 25 triangle

### Acute scalene triangle.

Sides: a = 21   b = 22   c = 25

Area: T = 218.4865697472
Perimeter: p = 68
Semiperimeter: s = 34

Angle ∠ A = α = 52.60774364381° = 52°36'27″ = 0.91881729769 rad
Angle ∠ B = β = 56.33884693605° = 56°20'18″ = 0.98332917859 rad
Angle ∠ C = γ = 71.05440942014° = 71°3'15″ = 1.24401278908 rad

Height: ha = 20.8088161664
Height: hb = 19.86223361339
Height: hc = 17.47988557978

Median: ma = 21.07772389084
Median: mb = 20.29877831302
Median: mc = 17.5

Inradius: r = 6.42660499257
Circumradius: R = 13.21659680629

Vertex coordinates: A[25; 0] B[0; 0] C[11.64; 17.47988557978]
Centroid: CG[12.21333333333; 5.82662852659]
Coordinates of the circumscribed circle: U[12.5; 4.29108987217]
Coordinates of the inscribed circle: I[12; 6.42660499257]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 127.3932563562° = 127°23'33″ = 0.91881729769 rad
∠ B' = β' = 123.662153064° = 123°39'42″ = 0.98332917859 rad
∠ C' = γ' = 108.9465905799° = 108°56'45″ = 1.24401278908 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.