Help me with this please quickly

8ft +10ft+10ft= 28ft

the perimeter of half a circle is

p=½πd+d

but in this case you won't add d since we're not going inside the circle therefore you use this formula ½πd

½×3.14×8 =12.56

12.56+ 28=40.56ft

hope it made sense

hello from mrbilldoesmath!

answer:

a(n) - a(n-1) -3

discussion:

this ones a bit interesting. given a(n) = 5 - 3n consider this:

a(n-1) = 5 - 3(n-1)

          = (5 - 3n) + 3             => but a(n) = 5 - 3n, the first term

          = a(n)   + 3                 => subtract 3 from both sides

a(n-1) -3 = a(n)  

or

a(n) - a(n-1) -3

you,

mrb

the square root of what number? if you add that, then someone will probably answer the question.