AC is not the diameter because the chord does not pass through the center.
Pentagon Integer: 360/5 = 72 degrees
Area of Circumscribed circle is?
(Need in Details, how you exactly you did)
2) Dog, Cat, and Mouse Prob.
[Land] [Animals][Person] [Lake] [Land]
The person can only take 1 animal across
Dog eats Cat
Cat eats Mice
Question: Minimum Trips to get everyone across? (Can go back and forth)
and I need the trips (ex: trip1: got the cat, trip2: went back, etc), not just the answer.
September 9th 2009, 07:24 PM
Your circle with regular pentagonal star.
1) Construct Angle Bisector at A
2) Construct Angle Bisector at B
3) Notice that you also just constructed the perpendicular bisector of AC.
4) Angle bisector from B intersects AC at point F. Label it.
5) The angle bisectors intersect at the Center of the circle. Call this O.
6) You have a right triangle, CFO.
7) Hypotenuse is Circle Radius.
8) Interior Acute Star angles are 36º. Half of that is 18º
9) cos(18º) = 5 / Radius.