Question 148550
Pentagon=540 degrees
540/5=108
108=the vertex angle of the isosceles triangle


1/2 of 108=54
tan(54)=x/10
x=13.764

(x=length of half of one side of the pentagon)
2x=27.528


apothem=10
perimeter=137.638


area=1/2ap


137.638(10)=1376.38


1376.38/2=688.19


area=688.19{{{cm^2}}}