Question 172190
Given the following:
{{{drawing(400,400,-6,6,-6,6,line(-4,-2,-4,2),line(4,2,4,-2),line(-4,2,4,2),line(4,-2,-4,-2),line(-4,2,4,-2),locate(-.20,-1.40,L=base=4in),locate(.30,.5,5in),blue(locate(0,1.8,AREA=12in^2)),red(locate(-4.5,0,W=3in)))}}}
We know, {{{A[R]=L*W}}}
But by Pyth Theorem:
{{{5^2=W^2+4^2}}} 
{{{W^2=5^2-4^2=25-16=9}}}
{{{W=sqrt(9)=3in}}}
Therefore,
{{{A=4*3=highlight(12sqin)}}}
thank you,
Jojo