Puzzle 5: Circles Crossword

A portion of the circumference of a circle.
The distance along the arc (Two Words)
a flat, or plane figure is the number of unit squares that can be contained within it.
the angle that forms when two radii meet at the center of a circle. (Two Words)
A shape with all points the same distance from its center.
The circle's perimeter.
A circle is a straight line segment whose endpoints both lie on the circle.
any straight line segment that passes through the center of the circle and whose endpoints lie on the circle.
An angle formed by two chords in a circle which have a common endpoint. (Two Words)
Is an arc of a circle having measure greater than or equal to. (Two Words)
Is an arc of a circle having measure less than or equal to. (Two Words)
Any of the line segments from its center to its perimeter, and in more modern usage, it is also their length.
The part of a circle enclosed by two radii of a circle and their intercepted arc.
A one-dimensional locus of points that forms half of a circle.
A line which touches a circle or ellipse at just one point.