Did i do this correct? Look at this website. i dont know if i did it right?

http://www.aasd.k12.wi.us/East/academics/math/Allen/IntMath2/Chapter7/section7.3.htm
look at #5

my work:
i used the equation A= .5aP
note: a is apothem. P is Perimeter

.5(70)(400)= 14,000
2 answers 2