# 40 40 48 triangle

### Acute isosceles triangle.

Sides: a = 40   b = 40   c = 48

Area: T = 768
Perimeter: p = 128
Semiperimeter: s = 64

Angle ∠ A = α = 53.13301023542° = 53°7'48″ = 0.9277295218 rad
Angle ∠ B = β = 53.13301023542° = 53°7'48″ = 0.9277295218 rad
Angle ∠ C = γ = 73.74397952917° = 73°44'23″ = 1.28770022176 rad

Height: ha = 38.4
Height: hb = 38.4
Height: hc = 32

Median: ma = 39.39554312072
Median: mb = 39.39554312072
Median: mc = 32

Inradius: r = 12
Circumradius: R = 25

Vertex coordinates: A[48; 0] B[0; 0] C[24; 32]
Centroid: CG[24; 10.66766666667]
Coordinates of the circumscribed circle: U[24; 7]
Coordinates of the inscribed circle: I[24; 12]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 126.8769897646° = 126°52'12″ = 0.9277295218 rad
∠ B' = β' = 126.8769897646° = 126°52'12″ = 0.9277295218 rad
∠ C' = γ' = 106.2660204708° = 106°15'37″ = 1.28770022176 rad

# How did we calculate this triangle?

### 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    