Pace out a real garden. Sketch it on paper to scale. Calculate the area. You've just done the maths a landscaper does every day.
Splitting an awkward shape
Real gardens are rarely neat rectangles. Slice the plot into rectangles and right triangles with straight cuts, find each piece's area, then add them up. Surveyors did exactly this for centuries before lasers.
Pacing tip: walk a known 10 m distance and count your paces, then divide — that gives your pace length. Now you can 'measure' any garden by walking it.
An L-shaped garden is a 10 m × 6 m rectangle with a 4 m × 3 m bite taken out of one corner. What's its area?
A rectangular plot is 12 paces by 8 paces. Your pace is 0.75 m. What's the area?
12 × 8 = 96 paces². Each pace² is 0.75 × 0.75 = 0.5625 m². So 96 × 0.5625 ≈ 54 m².
For weird shapes, divide into rectangles and triangles. Add the areas. This is exactly how surveyors did it for centuries.