A(r) is a function that gives area of a circle with radius r. it can be written in equation form as a(r)=3.14r to the secon dpower what is the value of a(4)

This is a common circle area question. just plug 4 wherever r and solve. in this case, A(4)= (3.14)(4)^2. type this into a calculator, (but use the actual pi button to get the best results) and you get 50.26548246 .