θ in degrees from positive x-axis.
Polar points (r₁,θ₁) and (r₂,θ₂) with non-negative radii and angles in degrees are converted to Cartesian, then distance uses the law of cosines: d² = r₁² + r₂² − 2r₁r₂ cos(θ₂−θ₁). Tiny negative roundoff inside the square root is clamped to zero.
This calculator uses plain decimal numbers. If a result looks wrong, check whether you used a comma instead of a dot (or vice versa) where the field expects one.