Question 1097462
Let {{{ s }}} = the side of the square base
The height is {{{ h }}} m
{{{ 20 = h*s }}}
{{{ s = 20/h }}}
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The  cost of the glass is:
{{{ 10*( 20/h ) + 10*4*h*(20/h) }}}
{{{ 200/h + 800 }}}
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The cost of the frame is:
{{{ 10*4*( 20/h ) + 10*4*( 20/h ) }}}
{{{ 800/h + 800/h }}}
{{{ 1600/h }}}
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{{{ C = 200/h + 800 + 1600/h }}}
{{{ C = 1800/h + 800 }}}
Chck the math and get another opinion if needed