# 4 7 8 triangle

### Acute scalene triangle.

Sides: a = 4   b = 7   c = 8

Area: T = 13.99877676792
Perimeter: p = 19
Semiperimeter: s = 9.5

Angle ∠ A = α = 29.99547255274° = 29°59'41″ = 0.52435067187 rad
Angle ∠ B = β = 61.02884677763° = 61°1'42″ = 1.06551477001 rad
Angle ∠ C = γ = 88.97768066963° = 88°58'37″ = 1.55329382348 rad

Height: ha = 6.99988838396
Height: hb = 3.9999362194
Height: hc = 3.49994419198

Median: ma = 7.24656883731
Median: mb = 5.26878268764
Median: mc = 4.06220192023

Inradius: r = 1.47334492294
Circumradius: R = 4.00106379077

Vertex coordinates: A[8; 0] B[0; 0] C[1.93875; 3.49994419198]
Centroid: CG[3.31325; 1.16664806399]
Coordinates of the circumscribed circle: U[4; 0.07114399626]
Coordinates of the inscribed circle: I[2.5; 1.47334492294]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 150.0055274473° = 150°19″ = 0.52435067187 rad
∠ B' = β' = 118.9721532224° = 118°58'18″ = 1.06551477001 rad
∠ C' = γ' = 91.02331933037° = 91°1'23″ = 1.55329382348 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.