# 2.1 7.2 7.5 triangle

### Right scalene triangle.

Sides: a = 2.1   b = 7.2   c = 7.5

Area: T = 7.56
Perimeter: p = 16.8
Semiperimeter: s = 8.4

Angle ∠ A = α = 16.26602047083° = 16°15'37″ = 0.28437941092 rad
Angle ∠ B = β = 73.74397952917° = 73°44'23″ = 1.28770022176 rad
Angle ∠ C = γ = 90° = 1.57107963268 rad

Height: ha = 7.2
Height: hb = 2.1
Height: hc = 2.016

Median: ma = 7.27661597014
Median: mb = 4.16877331968
Median: mc = 3.75

Inradius: r = 0.9
Circumradius: R = 3.75

Vertex coordinates: A[7.5; 0] B[0; 0] C[0.588; 2.016]
Centroid: CG[2.696; 0.672]
Coordinates of the circumscribed circle: U[3.75; 0]
Coordinates of the inscribed circle: I[1.2; 0.9]

Exterior(or external, outer) angles of the triangle:
∠ A' = α' = 163.7439795292° = 163°44'23″ = 0.28437941092 rad
∠ B' = β' = 106.2660204708° = 106°15'37″ = 1.28770022176 rad
∠ C' = γ' = 90° = 1.57107963268 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    