Measuring an object in Photoshop

To measure an object, follow these steps:
1. Select the Measure tool.
It’s tucked away in the Tools palette with the Eyedropper. Press I to cycle among the Eyedropper, Color Eyedropper, and Measure tool until it appears.
2. Click at a starting location for the measuring line and then drag to the end location.
Hold down the Shift key to constrain the line to multiples of 45 degrees.
3. Release the mouse button to create the measurement line.

Measuring an angle in Photoshop
You can measure an angle by drawing two lines and reading the angle between them from the
Options bar. Just follow these steps:
1. Select the Measure tool.
2. Click at a starting location for the first line and drag to the end location.
You can hold down the Shift key to constrain the line to multiples of 45 degrees.
3. Release the mouse button to create the first line.
4. Hold down the Alt key (or the Option key on the Mac) and click in the end point of the first line where you want to measure the angle.
5. Drag the second line and release the mouse button when it is finished.
6. In the Options bar, read the angle between the two lines (A).
You can also see the length of each of the lines as D1 and D2.