3-Point Radius measurement

The 3-Point Radius measurement tool lets you create a markup that measures the radius of an arc. The tool always starts with an arc, but you can resize it to form a full circle after placement. If you need to create a circular markup that calculates the radius immediately, use the Center Radius Measurement tool instead.

Before you start, set the page scale for your document first. If you try to place a measurement on a page without a scale, you'll be prompted to set one.