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Geometry lessons
Construct and discuss lines, angles, arcs, and diagrams while learners follow the process in real time.
Precision & teaching tools
On-screen ruler and protractor for Windows
Measure, demonstrate angles, draw arcs, read live coordinates, and magnify small details with precision tools designed for classrooms, whiteboards, CAD walkthroughs, and technical presentations.
Windows 10/11 · Ruler, protractor & compass · Feature availability varies by plan
Use precision instruments directly over the screen or whiteboard.
On-screen rulerGuide straight construction
ProtractorDemonstrate angles
CompassConstruct arcs and circles
CoordinatesTrack screen positions
Accuracy beyond quick markup
Explain measurements and geometry where viewers can see them
Combine precision instruments with ink, shapes, text, the whiteboard, and focus tools instead of switching between separate apps.
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CAD and technical walkthroughs
Point to dimensions, align visual explanations, and magnify small interface or drawing details.
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Screen and UI demonstrations
Use live coordinates and magnification to explain positions, layouts, and pixel-level details more clearly.
Precision toolkit
Measure, align, construct, and inspect
Use the right visual instrument for the explanation, then combine it with normal annotation or whiteboard tools.
✓
Ruler
Guide straight lines and measurements while working over supported Windows content or the whiteboard.
✓
Protractor
Demonstrate and construct supported angles directly where the audience is looking.
✓
Compass
Create supported arcs and circular constructions for geometry and technical explanations.
✓
Snap-to-angle
Keep supported lines and constructions aligned to consistent angles for cleaner visual results.
✓
Live coordinate readout
Track on-screen positions while drawing, reviewing an interface, or explaining a layout.
✓
Magnifier
Inspect small elements and pixel-level details without losing the surrounding context.
Accuracy note: these are visual teaching and demonstration tools. For regulated, engineering, manufacturing, or safety-critical measurements, verify results with an appropriate calibrated application or instrument.
Three-step workflow
Build a precise visual explanation
Open the content, choose the right precision instrument, and combine it with annotations that explain the result.
Prepare the content
Open a diagram, whiteboard, CAD view, lesson, image, or interface and launch OS Pen.
Choose a precision tool
Select the ruler, protractor, compass, coordinates, snap-to-angle, or magnifier for the task.
Demonstrate and capture
Add ink, labels, shapes, or focus cues, then save the supported session or capture the visual result.
Precision-tool questions
Frequently asked questions
Does OS Pen include an on-screen ruler and protractor?
Yes. OS Pen includes supported ruler and protractor tools for Windows, along with a compass, snap-to-angle, coordinates, and magnification tools.
Can I use the precision tools while teaching geometry?
Yes. Teachers and trainers can use the ruler, protractor, compass, drawing tools, and whiteboard together for geometry and technical explanations.
What does snap-to-angle do?
Snap-to-angle helps align supported constructions to consistent angles, making diagrams and demonstrations easier to control.
Does OS Pen show live screen coordinates?
Yes. Supported precision tools include a live coordinate readout that helps identify on-screen positions while drawing or demonstrating.
Can I magnify small screen details?
Yes. The magnifier supports close inspection of small interface elements, diagrams, layouts, and pixel-level details during supported Windows workflows.
Add precision to your next explanation
Download OS Pen and compare plans for the complete ruler, protractor, compass, whiteboard, and presentation toolkit.