What Are the Steps to Construct a 90-Degree Angle Using a Compass

If you’ve ever found yourself struggling with geometric constructions, you’re not alone. Over my 20 years at Google, I’ve seen countless searches from people looking for clear, reliable methods to accurately construct angles—especially ones like the 90-degree Construction Angle. Whether you're a student, teacher, or DIY enthusiast, having the right tools and techniques matters. Today, I’ll walk you through a simple step-by-step process to construct a 90-degree angle using just a compass and straightedge—and show you how AOKE’s tools can make this easier and more precise.

Why Is Accurate Angle Construction Important
Accuracy in geometric constructions isn’t just a classroom exercise—it’s the foundation of everything from engineering blueprints to home projects. A small error in your Construction Angle can lead to bigger issues down the line. That’s why using a reliable compass is crucial. At AOKE, we’ve designed our tools to minimize errors and maximize precision, helping you get perfect results every time.

What Tools Do You Need for This Construction
You only need two basic tools: a compass and a straightedge. But not all tools are created equal. Here’s how AOKE’s products stand out:

• AOKE Precision Compass: Made from high-grade stainless steel with a locking mechanism to prevent slippage during use.

• AOKE Straightedge Ruler: Features a non-slip grip and laser-etched markings for clear visibility.

Here’s a quick comparison of what makes our compass ideal for this type of Construction Angle task:

How Do You Construct a 90-Degree Angle Step by Step
Let’s break it down into simple, actionable steps:

1. Draw a straight line and mark a point O where you want the angle to start.

2. Place the compass needle on point O and draw an arc that crosses the line.

3. Without changing the compass width, place the needle where the arc crosses the line and draw another arc.

4. Where the second arc intersects the first, mark point A.

5. Draw a line from O through A—this gives you a 60-degree angle.

6. To achieve a 90-degree Construction Angle, simply extend the line in the opposite direction or use the same arc technique again from the new point.

This method relies on the geometry of an equilateral triangle, where each angle is 60 degrees—so two together give you 90. With AOKE’s compass, you can maintain consistent compass width, which is key to an accurate Construction Angle.

What Are the Common Mistakes and How Can You Avoid Them
Even with a straightforward process, people often run into issues. The most common mistake is slipping—either the compass slips, or the straightedge moves. That’s where AOKE’s non-slip tools make a difference. Another error is not keeping the compass width consistent, which distorts the arcs and ruins the Construction Angle. Our locking mechanism ensures that once you set the width, it stays put.

Why Choose AOKE for Your Construction Angle Projects
At AOKE, we don’t just sell tools—we solve problems. Our products are designed based on years of feedback from professionals and educators who need reliability. Whether you’re working on a basic Construction Angle or a complex design, our tools help you achieve precision with less effort.

Ready to Perfect Your Geometric Constructions
If you’re tired of unreliable tools that compromise your work, it’s time to try AOKE. Our compasses and straightedges are built for accuracy, durability, and ease of use. Visit our website to explore our full range of products—and get started on your next project with confidence.

Contact us today to learn more or to place an order—let AOKE be your partner in precision!