Mapping, Platting, and Subdivision
Core concepts
Know plat requirements, the distinction between a plat and a map, and the elements a subdivision plat must show (boundaries, lot lines, dimensions, bearings, curve data, dedications, signatures, and certifications). Understand curve terminology-radius, delta, tangent, length, chord, and degree of curve-and how to compute them. Know the difference between a record plat and an as-built, and the role of lot-and-block versus metes-and-bounds descriptions.
Traps
Examiners test whether you can compute curve length from degree of curve (arc definition vs. chord definition). Another trap is a plat that omits a required certification or dedication-questions ask which omission invalidates recording. Also watch for confusion between bearing and azimuth and between chord and arc length.
Rule of thumb
For arc definition, degree of curve D = 5729.578/R (feet). Arc length L = R × Δ (radians) = 100 × (Δ/D).
Worked example
A curve has R = 572.958 ft and Δ = 30°. D = 5729.578/572.958 ≈ 10°. Arc length L = 100 × (30/10) = 300 ft.