Question 942052
{{{drawing(500,300,-1400,100,-100,800,
rectangle(0,0,20,750),
triangle(-630,0,0,0,0,750),
triangle(-1300,0,0,0,0,750),
rectangle(0,0,-20,20),
blue(line(-1400,0,100,0)),
locate(-40,400,h),locate(-350,50,x),
locate(-1000,50,670ft),
red(arc(-1300,0,400,400,-30,0)),
locate(-1200,80,red(30^o)),
red(arc(-630,0,300,300,-50,0)),
locate(-570,80,red(50^o))
)}}} {{{system(x=h*cot(50^o),670ft+x=h*cot(30^o))}}}--->{{{670ft+h*cot(50^o)=h*cot(30^o)}}}--->{{{670ft=h*cot(30^o)-h*cot(50^o)}}}--->{{{670ft=h*(cot(30^o)-cot(50^o))}}}--->{{{h=670ft/(cot(30^o)-cot(50^o))}}}--->{{{h=highlight(750ft)}}} (rounded to the nearest foot).