I managed to get 11 pieces.
No, because, none of the combinations of lines can evenly slit spaces. Fold the circle first, and then you can cut the circle into 5 pieces with 2 straight lines.
Oval
None, circles aren't straight lines.
12:00 to 7:00,7:00 to 2:00,2:00 to 9:00
A circle has infinitely many points of symmetry. Every straight line that passes through the center of a circle is a line of symmetry.
No, because, none of the combinations of lines can evenly slit spaces. Fold the circle first, and then you can cut the circle into 5 pieces with 2 straight lines.
You did not specify if these are straight lines. If the lines are straight then no, only 7. If you curve the lines then, yes.
16
There are eleven.
No. A circle has no straight lines. You can approximate circles with very small straight lines (that's how a computer draws circles) but mathematically, no.
No, parallel lines are straight lines.
No, all polygons have straight lines. All lines are straight
Oval
No. A polygon is a plane area which is bounded by straight lines. A circle does not consist of straight lines.
The diameter is a straight line from one side of the circle to the other which passes through the centre of the circle. The radius is a straight line from the centre to the boundary of the circle. To label them, you could either write the words alongside the lines or, if the circle is too small, draw arrows from the two lines to outside the circle and write the words at the end of the arrow.
A chord is a straight line drawn through a circle which divides the circle into two parts. The line can be drawn anywhere in the circle EXCEPT the center where it becomes the diameter.
None, circles aren't straight lines.