Across
- 3. 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.
- 4. The longest side opposite the right angle in a right triangle.
- 8. The point on a line segment that divides the given line segment into two congruent parts.
- 12. Often referred to as the right cone. A cone is a solid formed by rotating a right triangle around one of its legs
- 13. A plane figure bounded by three or more straight-line sides.
- 14. angle 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. The boundary line of a circle or the length of such a boundary line.
- 17. angles Two angles in a plane which share a common vertex and a common side but do not overlap. Angles 1 and 2 below are adjacent angles.
- 19. An initial proposition or statement that is generally accepted as true without proof (self-evident truth) and from which further statements, or theorems, can be derived by using logical deduction.
- 21. A general conclusion proved upon general assumptions.
- 22. Also called half-line. It is a straight line that extends from a point.
- 24. A tubular solid with a circular base. Usually, this term implies a right cylinder that can be formed by rotating a rectangle about one of its sides.
- 26. 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.
- 27. 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.
- 28. In plane geometry, when one figure fits exactly on top of the other through simple translation and/or rotation, then these two figures are congruent.
- 29. 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.
- 30. A geometric object that has no dimension and is used to indicate a location.
- 31. Points or lines that all lie in the same plane.
- 32. Two lines that intersect at right angles.
- 35. angle An angle that is between 90° and 180°.
- 37. Lying on the same straight line.
- 39. The distance from the center of a circle to any point on its circumference.
- 41. Two or more straight coplanar lines that do not intersect.
- 43. term denominator of zero.
Down
- 1. A straight line along which two faces of a solid meet. A rectangular solid has twelve edges.
- 2. segment Part of a line between two points called endpoints.
- 3. The length of the boundary around a shape or a figure.
- 5. A three-dimensional figure bounded by plane polygonal faces. The point at which three or more faces meet is called a vertex. A line along which two faces meet is called an edge.
- 6. Two rays sharing a common endpoint. Angles are typically measured in degrees or radians.
- 7. Two angles that add up to 180°.
- 9. rays opposite straight lines that extends from a point.
- 10. pair 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.
- 11. A unit of measure used to measure the magnitude of an angle, equal in magnitude to 1/360 of a complete revolution.
- 15. If the sum of the measures of two angles is 90°, the angles are called complementary. Whenever two angles are complementary, each angle is said to be the complement of the other angle.
- 16. An additional geometric figure that is constructed to assist in solving a problem or producing a proof.
- 18. polygon When at least one of the interior angles of a polygon is greater than 180°, it is a concave polygon. The inside surface of a bowl is concave when viewed from above.
- 20. polygon 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.
- 23. angle An angle that has measure less than 90°.
- 25. A straight line or a plane that divides a line, a plane, an angle, or a shape into two equal parts.
- 30. A set of logical arguments used to deduce or prove a mathematical theorem from a set of axioms.
- 32. A polyhedron with two parallel, congruent polygons being its bases and all the other faces being parallelograms.
- 33. A pair of numbers that describe the position of a point on a coordinate plane by using the horizontal and vertical distances from the two reference axes.
- 34. angles the pair of angles opposite each other formed by two intersecting lines.
- 36. Also called non-coplanar lines. They are straight lines that are neither parallel, nor intersecting. They lie in different planes.
- 38. A polyhedron whose one face is a polygon and the other faces are triangles with one common vertex.
- 40. A point at which the two rays of an angle meet or the intersection point of two sides of a plane figure.
- 42. The surface included within a closed figure, measured by the number of square units needed to cover the surface.
- 44. A planar surface of a solid figure.