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Across 2. Relating to or on the side. 6. Through a given point there passes _______ plane perpendicular to a given line. 9. The ________ of a triangle is the perpendicular segment from a vertex to a line that contains the 11. it is the curved surface formed by lines (generators) joining a fixed point (vertex) to the points on a curve, the generators being extended indefinitely in both directions 14. If two planes are perpendicular to the same _________, they are parallel 15. The number of planes containing a line and a point not on that line 18. Located at intersection of the angle bisectors. 19. Two planes that intersect to form a right dihedral angle are said to be_____ 22. A type of angle formed by the union of two half planes with a common edge 23. Lines in space that are neither parallel or intersecting 25. If a line is perpendicular to each of two __________ lines at their point of intersection, then the line is perpendicular to the plane determined by them. 26. A polyhedron with one face (known as the "base") a polygon and all 27. Located at intersection of the altitudes 28. The number of non collinear points that determine a plane

Down 1. If a plane intersects two ______________, then the intersection 3. Two of these that intersect determine a plane 4. If________ planes are perpendicular to each other, then one plane contains a line perpendicular to the second plane. 5. Lines in the same plane that do not interesct 7. The ___________ of a triangle is a segment from a vertex to the midpoint of the opposite side 8. The locus of all points (in 3-dimensional space) whose distance from C is equal to r 10. The medians of a triangle intersect at a point that is __________of the distance from each vertex to the midpoint of the opposite side. 12. Lines are two or more lines that intersect in one point 13. Located at intersection of the medians 16. Two lines perpendicular to the same plane are 17. Located at intersection of the perpendicular bisectors of the sides 20. is a surface, consisting of points on the lines (generators) drawn through the points on a fixed curve and parallel to a fixed line, the generators being extended indefinitely in both directions. 21. The________of a dihedral angles is equal to the measure of the plane angle formed by two rayseach in a different half plane of the angle and each perpendicular to the common edge at the same point of the edge 24. A polyhedron possessing two congruent polygonal faces and 26. The type of angle formed by 2 rays in the samae plane