you just need to tap space bar and it will switch to the four panel layout (or whatever the last layout was)
then hold the mouse over the side view panel and tap spacebar again

if it doesn't revert to the four pane view layout thing then just click the button on the tool bar onthe left
its the button that has four little squares and three of them have little + shapes

these are your orthographic views, top, front, and side in the same layout you'd have them if you were drawing it on paper