Equivalent halves and quarters

Video description

Stable top-down view of two identical white discs on a light grey background. The left disc is divided by a single vertical line into two equal halves; its right half is filled orange. The right disc is divided by one vertical and one horizontal line into four equal quarters; its two left-hand quarters (top and bottom) are filled with the same orange. Both coloured regions cover exactly the same area: one half equals two quarters.