For rotating the images just do the following:
1. Click the image you wish to rotate and pick the Free Transform Tool from the left toolbar.
2. Take your mouse pointer outside the image. The cursor will change to the rotation icon.
3. Drag the cursor clockwise (or counterclockwise) to rotate the image.
To rotate the images using the Properties toolbar:
1. Click the element.
2. Enter a number in the field or use the arrows to adjust the rotation angle.