In Photoshop, there are a few different ways to draw a diagonal line. The first way is to use the Pen tool.
To do this, simply click on the Pen tool in the toolbar, then click and drag to draw your line. You can also use the Line tool, which is located under the Shape tool in the toolbar. Just click and drag to draw your line.
If you want to draw a straight line, you can hold down the Shift key while you click and drag. This will constrain the line to a straight line.
You can also use the Brush tool to draw a diagonal line. Just select the Brush tool and then click and drag to draw your line.
To change the color of your line, simply click on the color swatch in the toolbar. This will open up the Color Picker, where you can choose any color you like.
Once you have drawn your line, you can add a style to it by clicking on the “Stroke” option in the toolbar. This will open up a menu where you can choose from various stroke options, such as changing the width of the line or adding a dashed effect.
Finally, if you want to save your work, simply go to File > Save As and choose a location to save your file.