75%
A polar coordinate system defines points by their radial distance from a central pole ($r$) and their angular direction from a horizontal reference axis ($\theta$). Polar paper is essential in trigonometry, navigation, radio frequency engineering, and acoustic transducer design.
Audio engineers and RF technicians map microphone polar pickup patterns (cardioid, omnidirectional, figure-8) and loudspeaker dispersion lobes directly on polar grids to measure decibel attenuation across 360 degrees of rotation.
For standard calculus coursework, 15-degree increments (24 radial rays) or 30-degree increments (12 rays) provide ample resolution. For laboratory instrumentation calibration, switch to 5-degree sectors (72 rays) for maximum angular precision.