# 13 25 26 triangle

### Acute scalene triangle.

Sides: a = 13   b = 25   c = 26

Area: T = 159.8799874843
Perimeter: p = 64
Semiperimeter: s = 32

Angle ∠ A = α = 29.45218475231° = 29°27'7″ = 0.51440317101 rad
Angle ∠ B = β = 71.00875361503° = 71°27″ = 1.23993152996 rad
Angle ∠ C = γ = 79.54106163266° = 79°32'26″ = 1.3888245644 rad

Height: ha = 24.58545961298
Height: hb = 12.78439899875
Height: hc = 12.29222980649

Median: ma = 24.66327249103
Median: mb = 16.31771688721
Median: mc = 15.10996688705

Inradius: r = 4.99437460889
Circumradius: R = 13.22196599157

Vertex coordinates: A[26; 0] B[0; 0] C[4.23107692308; 12.29222980649]
Centroid: CG[10.07769230769; 4.09774326883]
Coordinates of the circumscribed circle: U[13; 2.43998767232]
Coordinates of the inscribed circle: I[7; 4.99437460889]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 150.5488152477° = 150°32'53″ = 0.51440317101 rad
∠ B' = β' = 108.992246385° = 108°59'33″ = 1.23993152996 rad
∠ C' = γ' = 100.4599383673° = 100°27'34″ = 1.3888245644 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.