Vectorworks Tip #059 – Basic Trigonometry

When you’re creating landscape areas, Vectorworks tends to draw these as if they were projected down onto a flat plane. In reality, the site may be sloping, so the area of the site is actually greater than the plan area shown on the drawings. The difference between the plan area and the actual area can be calculated using basic trigonometry.
You need to know the plan area and you need to know the average slope, in degrees. The basic trigonometry for this is given by this formula. I’ve had a sketch with this formula on the back of my calculator since I was in high school. It really helps me to remember my basic trigonometry.

Comments

  1. This brings up a question that I have always wondered about. When a surveyor is measuring land in an area like the mountains are the bounds measured by the actual land (along the slope) or the projection from the air? If it is along the slope then you could not scale the property lines on a map. It would also throw off the buildable area ratio since the buildable area would always have to be perpendicular to the “plane in the sky”.
    Do you know what surveyors do?

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