A window is in the form of a rectangle surmounted by a semicircular opening. The total perimeter of the window is 10 meters. Find the dimensions of the window to admit maximum light through the whole opening. How having large windows help us in saving electricity and conserving environment?
Given:
• Total perimeter of window = 10m
Let the dimension of the window be 2x and 2y as shown
Perimeter of window = 2x + 4y + πx = 10
![]()

Area, ![]()
![]()
![]()
![]()
we get maxima for
as ![]()
For ![]()
So, the required dimensions are ![]()
Having large windows can help us in saving electricity in several ways. For example, we get proper light and air through the window which will definitely remove the need of bulb and fans thus saving electricity and hence saving the environment also.