In the 3-4-5 triangle layout method, which statement is true?

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Multiple Choice

In the 3-4-5 triangle layout method, which statement is true?

The method relies on a right triangle where the sides are in the 3:4:5 ratio. Triangles with the same side ratios are similar, so you can scale the whole triangle by any factor and still have a perfect right angle. That makes the important point that proportions can be scaled up or down: choose a longer baseline and lay off the corresponding 4 and 3 units (or any multiples) to preserve the right angle, or use a shorter baseline for a smaller layout, and you’ll still get a true perpendicular. A baseline is still needed to define the size you’re working with, so saying there’s no baseline isn’t accurate. Terrain grade can affect how measurements map to a plan or to horizontal distances, and a total station generally provides higher precision than a simple 3-4-5 layout, so that statement isn’t correct either.

The method relies on a right triangle where the sides are in the 3:4:5 ratio. Triangles with the same side ratios are similar, so you can scale the whole triangle by any factor and still have a perfect right angle. That makes the important point that proportions can be scaled up or down: choose a longer baseline and lay off the corresponding 4 and 3 units (or any multiples) to preserve the right angle, or use a shorter baseline for a smaller layout, and you’ll still get a true perpendicular.

A baseline is still needed to define the size you’re working with, so saying there’s no baseline isn’t accurate. Terrain grade can affect how measurements map to a plan or to horizontal distances, and a total station generally provides higher precision than a simple 3-4-5 layout, so that statement isn’t correct either.

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