Across
- 2. A perfect round ball. A closed solid bounded by a surface on which all points are equidistant from a central point called the center.
- 4. The boundary line of a circle or the length of such a boundary line.
- 6. Concepts that are not defined in terms of previously defined concepts
- 8. A can-shaped solid figure.
- 9. A statement accepted as true without proof. It should be so simple and direct that it seems to be unquestionably true.
- 11. A set of logical arguments used to deduce or prove a mathematical theorem from a set of axioms.
- 12. An angle that is greater than 180°.
- 13. 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.
- 15. Two angles that share the same vertex and have one side in common between them.
- 16. Is a solid formed by rotating a right triangle around one of its legs.
- 17. The pair of angles opposite each other formed by two intersecting lines.
- 22. 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.
- 24. Lying on the same straight line.
- 25. An angle with a measure between 0° and 90°.
- 27. Collinear rays with the same endpoint. They form a line.
- 30. When the sum of two angles measures 90°
- 31. A point B that lies on the line connecting two points A and C and has one of the two points on each side of it. The point B is said to be between points A and C if, and only if, AB + BC = AC, in which AB is the distance from A to B, BC is the distance from B to C, and AC is the distance from A to C.
- 32. Also called half-line. It is a straight line that extends from a point.
- 37. A straight line or a plane that divides a line, a plane, an angle, or a shape into two equal parts.
- 40. An angle that is between 90° and 180°.
- 42. A unit of measure used to measure the magnitude of an angle, equal in magnitude to 1/360 of a complete revolution.
- 43. Part of a line between two points called endpoints.
- 44. 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.
- 45. A planar surface of a solid figure.
- 46. The length of the boundary around a shape or a figure.
Down
- 1. Two distinct coplanar lines that do not intersect
- 3. 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 it is a line segment joining two vertices that are not in the same face.
- 4. Points or lines that all lie in the same plane.
- 5. A polygon that has at least one diagonal with points outside the polygon.
- 7. The point on a line segment that divides the given line segment into two congruent parts.
- 9. A space figure with two parallel polygonal bases that are the same shape and the same size.
- 10. At a 90° angle.
- 14. The side opposite the right angle in a right triangle.
- 16. Planar figures or solid shapes that have the same shape and size.
- 18. A line segment where two faces of a polyhedron meet.
- 19. The path of a point moving in opposite directions infinitely. It has neither width nor thickness but length. It is the shortest distance between two points.
- 20. Two angles that add up to 180°.
- 21. The figure formed by two rays from the same initial point. The two rays are called the sides of it and the initial point is called the vertex of it.
- 23. A polygon that has no diagonal with points outside the polygon
- 26. A pair of numbers that describe the position of a point on a plane by using the horizontal and vertical distances from the two reference axes.
- 28. A geometric object that has no dimension and is used to indicate a location.
- 29. Lines in three dimensional space that do not intersect and are not parallel.
- 30. An additional geometric figure that is constructed to assist in solving a problem or producing a proof.
- 33. The surface included within a closed figure, measured by the number of square units needed to cover the surface.
- 34. A polyhedron whose one face is a polygon and the other faces are triangles with one common vertex.
- 35. A closed plane figure bounded by at least three line segments.
- 36. A pair of adjacent angles formed by intersecting lines.
- 38. A general conclusion proposed to be proved upon the basis of certain given hypotheses or assumptions; or, a general conclusion that has been proved.
- 39. A line segment between the center and a point on the circle or sphere.
- 41. The corners of a polygon.