Let the radius of semicircle, length and breadth of rectangle be $r,$ $x$ and $y$ respectively
\[AE\text{ }=\text{ }r\]
\[AB\text{ }=\text{ }x=2r\text{ }\left( semicircle\text{ }is\text{ }mounted\text{ }over\text{ }rectangle \right)\ldots 1\]
\[AD\text{ }=\text{ }y\]
Given Perimeter of window \[=\text{ }10\text{ }m\]
\[x\text{ }+\text{ }2y\text{ }+\text{ }\pi r\text{ }=\text{ }10\]
\[2r\text{ }+\text{ }2y\text{ }+\text{ }\pi r\text{ }=\text{ }10\]
\[2y\text{ }=\text{ }10\text{ }\text{ }\left( \pi \text{ }+\text{ }2 \right).r\]
