Question

Find the area of a circle. use terms to pi. c=pi over 2. the answer is pi over 16. why?

Answer 1

C=2pi*r; circumference formula

a=pi*r^2; area formula

It says the circumference is pi/2; so undo that by using the circumference formula to solve for r(radius);

2pi*r=pi/2
pi crosses each other off, making 2r=1/2
(When something crosses itself out it becomes a 1)
2r=1/2
r=.25 (because 1/2 is 0.5, and 0.5 divided by 2 is .25)

Now use the r you have in the area formula.
a=pi*r^2
.25 squared is .0625

1 divided by .0625 is 16, so now you have
a=pi*.0625 this will get you 1/16th of pi, or pi divided by 16.

(1/16th if pi is the same as pi divided by 16)

.0625pi=pi/16