Yes, it can be done in Photoshop CS and in Elements, too
This is how I do it, Yusra - I made a small tutorial for you
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Note: Photoshop Elements actually has a preloaded quarter circle shape - it would seem, however, that CS5 does not ;-))
Open Photoshop CS, create a new workspace/document.
For visual/size purposes: create a grey rectangle of the size 1300 x 300 (choose “fixed size” under “style”) with the Rectangular Marquee Tool. This will help you to stick to what I call the sig boundaries, that way you won't have any size problems. In other words, you will work within this rectangle, but not outside its borders.
Create another layer, and draw a circle (press the "Shift" key on your keyboard while you use the Elliptical Marquee Tool; this will constrain the circle’s proportions and make it perfectly round) and fill it with black.
Go to “View” and enable “Rulers”. Now, with the “Move Tool”, drag horizontal and vertical guides (indicated in light blue in the image below) to the circle so that they meet in the exact centre (this is indicated by the Move Tool’s transform controls, so make sure that “Show Transform Controls” is activated.
Now you need only one quarter of this circle. With the Rectangular Marquee Tool (change the style to “Normal”), draw a rectangle over the circle so that the bottom edge meets the guide.
Then press the “Delete” key on your keyboard. This will remove the upper half of the circle. Next place a new rectangle over the right half of the remaining half of the circle and press “Delete” again. Now you’ve got just one quarter of the circle. Go to “View” and select “Clear guides”.
Move the quarter circle to the left side of the layer (you can resize it a bit so that it fits within the sig size boundaries).
Now hold the ALT key and tap the right arrow key at the same time. When you let go, the shape will look like this, and your layer palette will be full of layer copies.
Go to the layer palette, make sure the topmost layer is highlighted, scroll down to the very first layer of the quarter circle, press the “Shift” key on your keyboard, right click and merge and the layeres.
Duplicate the resulting shape layer. Make sure the duplicate layer is selected. Go to “Edit”, “Transform” and choose “Rotate 180°”. This will flip the duplicate layer; now, still making sure that this layer is highlighted in the Layer Palette, press the “Shift” and the right arrow keys at the same time. This will move the layer quickly to the right.
Make sure your layers are properly aligned and merge them. You’re done