If a 700px content area is floated left next to a 301px sidebar in a 1000px container, what will happen?

In a layout where a 700px content area is floated left next to a 301px sidebar within a 1000px container, the total width of the content area and the sidebar exceeds the width of the container. Specifically, if the content area is 700px and the sidebar is 301px, together they take up 1001px (700px + 301px = 1001px), which is greater than the 1000px available in the container.

When elements are floated, the browser attempts to position them side by side until there is not enough space left for them to fit within the defined width. In this case, since the combined width of the floated elements exceeds the container's width, the sidebar will be forced to overflow and thus, it will be rendered below the content area. This results in one being displayed below the other, which is what the answer indicates.

This behavior reflects how floating works in CSS. When you float an element, it takes it out of the normal document flow, but the natural layout still attempts to respect the boundaries of its container, leading to this outcome when the widths do not reconcile.