Geometry Crossword

1. a flat surface or area that extends infinitely in two dimensions and has no thickness.
5. The distance around the boundary of a circle.
9. a location.
10. two or more points are said to be collinear, if they lie on the same line.
12. formed when two straight lines or rays meet at a common endpoint.
13. a point that is exactly in the middle of the line segment joining two points.
15. a mathematical statement which appears to be true, but has not been formally proven.

2. the perpendicular drawn from the vertex of the triangle to the opposite side.
3. a straight set of points that extend in opposite directions.
4. a straight line that divides an angle or line into two equal parts.
6. to have the same shape and size.
7. a line with a single endpoint (or point of origin) that extends infinitely in one direction.
8. "lying on the same plane". Points that lie on the same plane.
11. a point where two lines or curves meet.
14. The portion of a line between any two of its points.