controlling circle area

Replies to This Discussion

Permalink Reply by sergiu ungureanu on May 17, 2010 at 3:17pm

If have grabbed a simple slider i would control only the radius, but I have figured it out like this.
Thanks anyway for replay.

Attachments:

• aria cercului copy.jpg, 63 KB

Permalink Reply by Danny Boyes on May 17, 2010 at 3:00pm

Rearrange the equation for a circle area
A = Pi*r^2 where r is the radius.
therefore r = sqrt(A/Pi) or (A/Pi)^0.5.

This can all be done in an F(x) expression component or with a Divide Component (Slider value divided by Pi) then into a Square root component (if there is one, I can't remember, if not a powers component with 0.5) this will give you the radius to plug into the circle.