Which triangles are similar?
A. 12 6
B. 8 16
C. 8 4
D. 3 6

Sides: a = 12   b = 12   c = 6

Area: T = 34.857

Perimeter: p = 30

Semiperimeter: s = 15

Angle ∠ A = α = 75.522° = 75°31'21″ = 1.318 rad

Angle ∠ B = β = 75.522° = 75°31'21″ = 1.318 rad

Angle ∠ C = γ = 28.955° = 28°57'18″ = 0.505 rad

Height: ha = 5.809

Height: hb = 5.809

Height: hc = 11.619

Median: ma = 7.348

Median: mb = 7.348

Median: mc = 11.619

Inradius: r = 2.324

Circumradius: R = 6.197

Vertex coordinates: A[6; 0] B[0; 0] C[3; 11.619]

Centroid: CG[3; 3.873]

Coordinates of the circumscribed circle: U[3; 5.422]

Coordinates of the inscribed circle: I[3; 2.324]

Exterior (or external, outer) angles of the triangle:

∠ A' = α' = 104.478° = 104°28'39″ = 1.318 rad

∠ B' = β' = 104.478° = 104°28'39″ = 1.318 rad

∠ C' = γ' = 151.045° = 151°2'42″ = 0.505 rad

because 1.2 isnt half of 6 duh