Across
- 3. term The "slope" of a vertical line. A vertical line has undefined slope because all points on the line have the same x-coordinate. As a result the formula used for slope has a denominator of 0, which makes the slope undefined..
- 5. Two distinct coplanar lines that do not intersect.
- 7. One of the line segments making up the framework of a polyhedron. The edges are where the faces intersect each other.
- 9. A three dimensional solid consisting of all points equidistant from a given point. This point is the center of the sphere. Note: All cross-sections of a sphere are circles.
- 11. On the coordinate plane, the pair of numbers giving the location of a point (ordered pair). In three-dimensional coordinates, the triple of numbers giving the location of a point (ordered triple). In n-dimensional space, a sequence of n numbers written in parentheses.
- 12. The amount of space inside of an object.
- 14. A closed plane figure for which all sides are line segments. The name of a polygon describes the number of sides. A polygon which has all sides mutually congruent and all angles mutually congruent is called a regular polygon.
- 15. Two acute angles that add up to 90°. For example, 40° and 50° are complementary.
- 19. A shape or solid which has an indentation or "cave". Formally, a geometric figure is concave if there is at least one line segment connecting interior points which passes outside of the figure.
- 20. At a 90° angle. Note: Perpendicular lines have slopes that are negative reciprocals.
- 25. Two rays sharing a common endpoint. Angles are typically measured in degrees or radians.
- 27. The distance around the outside of a plane figure. For a polygon, the perimeter is the sum of the lengths of the sides.
- 28. The result of taking the reciprocal of a number and then changing the sign
- 32. A corner point of a geometric figure. For a polygon, vertices are where adjacent sides meet. For an angle, the vertex is where the two rays making up the angle meet.
- 34. An additional geometric figure that is constructed to assist in solving a problem or producing a proof.
- 36. A three-dimensional geometric figure with parallel congruent bases. The bases can be shaped like any closed plane figure (not necessarily a circle) and must be oriented identically.
- 37. 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.
- 40. Lying in the same plane. For example, any set of three points in space are coplanar.
- 41. A unit of angle measure equal to of a complete revolution. There are 360 degrees in a circle. Degrees are indicated by the ° symbol, so 35° means 35 degrees.
- 42. A pair of adjacent angles formed by intersecting lines.
- 44. 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.
- 45. segment All points between two given points (including the given points themselves).
Down
- 1. A set of logical arguments used to deduce or prove a mathematical theorem from a set of axioms.
- 2. Two angles that add up to 180°.
- 4. A solid with no curved surfaces or edges. All faces are polygons and all edges are line segments.
- 6. A geometric figure with no indentations. Formally, a geometric figure is convex if every line segment connecting interior points is entirely contained within the figure's interior.
- 8. In the diagram below, angles 1 and 4 are vertical. So are angles 2 and 3. Vertical angles are angles opposite one another at the intersection of two lines. Vertical angles are congruent.
- 10. A part of a line starting at a particular point and extending infinitely in one direction.
- 13. Lying on the same line.
- 16. A 90° angle.
- 17. Point B is between points A and C if it is on the line segment connecting A and C.
- 18. The side of a right triangle opposite the right angle. Note: The hypotenuse is the longest side of a right triangle.
- 19. A complete circular arc. Circumference also means the distance around the the outside of a circle.
- 21. A line segment between two points on the circle or sphere which passes through the center. The word diameter is also also refers to the length of this line segment.
- 22. A three dimensional figure with a single base tapering to an apex. The base can be any simple closed curve. Often the word cone refers to a right circular cone.
- 23. A flat surface extending in all directions. Any three noncollinear points lie on one and only one plane. So do any two distinct intersecting lines. A plane is a two-dimensional figure.
- 24. The point halfway between two given points.
- 26. A line segment, line, or plane that divides a geometric figure into two congruent halves.
- 27. A solid with parallel congruent bases which are both polygons. The bases must be oriented identically. The lateral faces of a prism are all parallelograms or rectangles.
- 28. two rays with a common endpoint that form a line
- 29. suggest or assume the existence, fact, or truth of (something) as a basis for reasoning, discussion, or belief.
- 30. Lines in three dimensional space that do not intersect and are not parallel.
- 31. An angle that has measure less than 90°.
- 33. A polyhedron with a polygonal base and lateral faces that taper to an apex. A pyramid with a triangular base is called a tetrahedron.
- 35. An angle that has measure more than 90° and less than 180°.
- 36. Exactly equal in size and shape. Congruent sides or segments have the exact same length. Congruent angles have the exact same measure. For any set of congruent geometric figures, corresponding sides, angles, faces, etc. are congruent.
- 38. A line segment between the center and a point on the circle or sphere. The word radius also refers to the length of this segment.
- 39. One of the flat surfaces making up a polyhedron. Note: The faces of a polyhedron are all polygons.
- 43. The geometric figure formed at the intersection of two distinct lines.