Question 951886
{{{drawing(500,150,-1,4,-0.15,1.35,
line(-1,0,4,0),rectangle(3.29,0,3.19,0.1),
triangle(0,0,3.29,0,3.29,1.2),red(arc(0,0,1,1,-20,0)),
locate(0.5,0.25,red(20^o)),locate(1.65,0.6,3.5ft),
locate(3.2,0.7,h)
)}}} {{{h/"3.5 ft"=sin(20^o)}}}<-->{{{h="3.5 ft"*sin(20^o)}}}
Using the approximate value {{{0.342}}} for {{{sin(20^o)}}} we get
{{{h="3.5 ft"*0.342}}}--->{{{highlight(h=1.20ft)}}}(rounded).
Since {{{sin(20.05^o)=0.3428400}}} , {{{sin(20.06^o)=0.3430040}}} , and {{{2/3.5=0.342857}}} ,
with a height of {{{1.2ft}}} , the angle will be {{{20.05^o}}} , which is close enough.