Across
- 4. - A straight line or a plane that divides a line, a plane, an angle, or a shape into two equal parts.
- 6. - A point at which the two rays of an angle meet or the intersection point of two sides of a plane figure.
- 11. - A closed plane figure bounded by at least three line segments.
- 12. - The surface included within a closed figure, measured by the number of square units needed to cover the surface.
- 13. - An angle that is between 90° and 180°.
- 14. - Two or more straight coplanar lines that do not intersect.
- 15. - The path of a point moving in opposite directions infinitely. A line has neither width nor thickness but length. It is the shortest distance between two points.
- 16. - An angle with a measure between 0° and 90°.
- 17. - Also called non-coplanar lines. They are straight lines that are neither parallel, nor intersecting. They lie in different planes.
- 18. - Two lines that intersect at right angles.
- 20. - The distance from the center of a circle to any point on its circumference.
- 22. - A polyhedron whose one face is a polygon and the other faces are triangles with one common vertex. This polygon is the base of the pyramid. The other triangles are the lateral faces. The common vertex of these lateral faces is the vertex of the pyramid. The segment from the vertex perpendicular to the base is called the altitude of the pyramid. The length of the altitude is called the height of the pyramid. The intersections of the adjacent lateral faces are called the lateral edges of the pyramid.
- 24. - Intuitively speaking, curved away from the eye. A concave figure is a set of points some of whose chords include points that are in the set.
- 28. - Two angles that add up to 180°.
- 32. - A line segment that passes through the center of a circle and has its two endpoints on the circle. It also represents the length of such a line segment.
- 33. - A perfect round ball. A sphere is a closed solid bounded by a surface on which all points are equidistant from a central point called the center.
- 34. - A planar surface of a solid figure.
- 35. - A set of logical arguments used to deduce or prove a mathematical theorem from a set of axioms.
- 37. - Lying on the same straight line.
- 38. - Intuitively speaking, curved outward or toward the eye. A convex curve is a set of points any of whose chords do not include any point that is not in the set.
- 41. - A pair of angles that add up to 90°. As shown, 1 is the complementary angle of 2.
- 42. - An additional geometric figure that is constructed to assist in solving a problem or producing a proof.
- 43. - A geometric object that has no dimension and is used to indicate a location.
- 44. - A space figure with two parallel polygonal bases that are the same shape and the same size.
- 45. - Part of a line between two points called endpoints.
Down
- 1. - The point on a line segment that divides the given line segment into two congruent parts.
- 2. - A unit of measure used to measure the magnitude of an angle, equal in magnitude to 1/360 of a complete revolution.
- 3. - Planar figures or solid shapes that have the same shape and size.
- 5. - The figure formed by two rays from the same initial point. The two rays are called the sides of the angle and the initial point is called the vertex of the angle.
- 7. - A flat surface that can extend forever in length and width but has no thickness. The surface of a calm sea and a flat valley are all physical models of a plane.
- 8. - A pair of adjacent angles formed by intersecting lines. Angles 1 and 2 below are a linear pair. So are angles 2 and 4, angles 3 and 4, and angles 1 and 3. Linear pairs of angles are supplementary.
- 9. - The boundary line of a circle or the length of such a boundary line.
- 10. - Also called half-line. It is a straight line that extends from a point.
- 11. - The length of the boundary around a shape or a figure.
- 12. - Two angles that share the same vertex and have one side in common between them.
- 13. - Two rays with a common endpoint that point in opposite directions and form a straight line.
- 19. - A line segment where two faces of a polyhedron meet.
- 21. - Another name for analytical geometry.
- 23. - A solid bounded by at least four polygonal faces. The pairs of faces meet along their edges. Three or more edges meet in each vertex. A diagonal of a polyhedron is a line segment joining two vertices that are not in the same face.
- 25. - Points or lines that all lie in the same plane.
- 26. - The pair of angles opposite each other formed by two intersecting lines.
- 27. - A statement accepted as true without proof. A postulate should be so simple and direct that it seems to be unquestionably true.
- 29. - Can be combined to define other terms.
- 30. - An angle that measures 90° or /2 radians. It is the angle between two perpendicular lines such as the corner of a square or two perpendicular planes such as the wall and the ground.
- 31. - A general conclusion proposed to be proved upon the basis of certain given hypotheses or assumptions; or, a general conclusion that has been proved, e.g., Pythagorean Theorem, Binomial Theorem, Fundamental Theorem of Algebra, etc.
- 36. - When two lines intersect, four angles are formed. The angles that are directly opposite to each other are called Opposite Angles.
- 37. - A can-shaped solid figure.
- 38. - Often referred to as the right cone. A cone is a solid formed by rotating a right triangle around one of its legs.
- 39. - Having one thing on either side of it. 2 is between 1 and 3.
- 40. - The side opposite the right angle in a right triangle.