Posts tagged 'matrices'

F.47 The UVW Coordinate Triangle

Placing the altitude foot H_C at the origin (0, 0) with A = (-U, 0), B = (W, 0), and C = (0, V) parameterizes any triangle by three numbers (U, V, W) with a = sqrt(V^2 + W^2), b = sqrt(U^2 + V^2), c = U + W, and reduces the cevian traces D, E, F through P(p, q) to explicit 2x2 rational matrix formulas.

F.54 HP-35s Triangle Program and Coordinate Scripts

In the canonical frame A = (0, 0), B = (M, 0), C = (I, J), the forward and inverse barycentric-Cartesian transformations BARY 2 CAR and CAR 2 BARY are given by P = M U + I V, Q = J V and V = Q / J, U = (P - I V) / M, T = 1 - (U + V).