# 4 4 7 triangle

### Obtuse isosceles triangle.

Sides: a = 4   b = 4   c = 7

Area: T = 6.77877208559
Perimeter: p = 15
Semiperimeter: s = 7.5

Angle ∠ A = α = 28.95550243719° = 28°57'18″ = 0.50553605103 rad
Angle ∠ B = β = 28.95550243719° = 28°57'18″ = 0.50553605103 rad
Angle ∠ C = γ = 122.0989951256° = 122°5'24″ = 2.1310871633 rad

Height: ha = 3.38988604279
Height: hb = 3.38988604279
Height: hc = 1.93664916731

Median: ma = 5.3398539126
Median: mb = 5.3398539126
Median: mc = 1.93664916731

Inradius: r = 0.90436961141
Circumradius: R = 4.1311182236

Vertex coordinates: A[7; 0] B[0; 0] C[3.5; 1.93664916731]
Centroid: CG[3.5; 0.64554972244]
Coordinates of the circumscribed circle: U[3.5; -2.19546905629]
Coordinates of the inscribed circle: I[3.5; 0.90436961141]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 151.0454975628° = 151°2'42″ = 0.50553605103 rad
∠ B' = β' = 151.0454975628° = 151°2'42″ = 0.50553605103 rad
∠ C' = γ' = 57.91100487437° = 57°54'36″ = 2.1310871633 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.