Adding Features - Intersect

📝 Overview

The Intersect function allows you to fix a new point by linear measurement from two or three known points. It does this by creating circles from the known points at specified distances and determining their intersection(s).

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2️⃣ Two Point Method

Use this method when you wish to add a point that is equidistant from two known points:

1. Click (or Snap) onto the first known point.

2. Drag out a circle to the required distance — either by watching the radius display on the status line, or by right-clicking and typing in the distance value in the dialog box.

3. Repeat for the second known point.

This produces two overlapping circles, creating two possible intersection points.

• Both points are equidistant from the two known points.

• Click on the intersection that represents the point you require.

⚠️ Warning: The system cannot know which intersection you intend to use — you must select one.

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3️⃣ Three Point Method

Use this method when you have three known points:

1. Click (or Snap) onto the first point and drag out a circle at the required distance.

2. Repeat for the second point.

3. Repeat for the third point.

You will see three circles intersect, forming a very small triangular area. The resultant point is the calculated midpoint of the intersection.

🔎 Resultant Point Behaviour

The snap-point created will always be within the smallest segment formed by the three circles, but not always inside all of them:

• ✅ Inside all three circles → Normally occurs if circles are equidistant.

• ✅ Inside two circles → Larger circle creates a small overlapping segment inside the other two.

• ✅ Inside one circle only → Smallest segment is formed outside the two smaller circles.

• ✅ Outside all three circles → Circles overlap only slightly, but the snap point is created outside them. Useful for finding a location beyond the given ranges of the starting points.

💡 Handy hint: Even when the resultant point is not inside all three circles, the intersection is still valid and can be useful for offset positioning.

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🎯 Special Case: First Intersection as Last Point in Polyline

(Not applicable for symbols)

If you wish the first circle’s centre point to be fixed on the last point in a polyline:

1. Position the cursor within tolerance over the last point in the polyline.

   • The Brg: Dist: display should read zero or a very small value.

2. Right-click to open the menu.

3. Select Intersect.

This ensures the first circle is centred precisely on the last point of the polyline.