Answer:
Sides: a = 5 b = 7 c = 9
Area: T = 17.412
Perimeter: p = 21
Semiperimeter: s = 10.5
Angle ∠ A = α = 33.557° = 33°33'26″ = 0.586 rad
Angle ∠ B = β = 50.704° = 50°42'13″ = 0.885 rad
Angle ∠ C = γ = 95.739° = 95°44'21″ = 1.671 rad
Height: ha = 6.965
Height: hb = 4.975
Height: hc = 3.869
Median: ma = 7.665
Median: mb = 6.384
Median: mc = 4.093
Inradius: r = 1.658
Circumradius: R = 4.523
Vertex coordinates: A[9; 0] B[0; 0] C[3.167; 3.869]
Centroid: CG[4.056; 1.29]
Coordinates of the circumscribed circle: U[4.5; -0.452]
Coordinates of the inscribed circle: I[3.5; 1.658]
Exterior (or external, outer) angles of the triangle:
∠ A' = α' = 146.443° = 146°26'34″ = 0.586 rad
∠ B' = β' = 129.296° = 129°17'47″ = 0.885 rad
∠ C' = γ' = 84.261° = 84°15'39″ = 1.671 rad
Step-by-step explanation: