Measuring 45° Miter & Corner Angles

How to Measure This Angle on an Image or Photo

A 45-degree angle bisects a perfect right angle (90°). In woodworking and miter framing, cutting two 45° pieces creates a seamless 90° corner joint. When measuring on an image, align ray A with your base edge and ray C with your miter line.

Step-by-Step Measurement Procedure

1. Upload your image: Drag and drop a photo or blueprint onto the Online Protractor canvas.
2. Position Point B (Vertex): Drag the central vertex dot directly onto the corner or angle origin.
3. Align Ray A (Baseline): Drag the left handle so ray A aligns perfectly with your reference line.
4. Adjust Ray C (Angle Ray): Drag the right handle until ray C lies exactly along the sloped edge.
5. Read Angle Output: The tool displays degrees, radians, complementary, and supplementary angles in real time.