Geometry Important Terms

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Across
  1. 5. The sum of two angles whose measure is 90. The angles form a right angle.
  2. 8. Lines meet at a 90-degree angle. Any horizontal line and a vertical line.
  3. 9. Sum of the areas of all the faces. This does include the bases of the shape.
  4. 12. Angle whose measure is less than 90. The smallest kind of angle.
  5. 13. Length of a line segment from its center to its perimeter. Half of the diameter.
  6. 16. Points are two rays that form an angle. Formed by 2 intersecting lines, it refers to a corner of the shape.
  7. 17. The sum of two angles whose measure is 180. The straight line at the bottom makes it this.
  8. 20. Any straight line segment that passes through the center of a circle and whose endpoints lie on the circle. This gets you the radius if you divide by 2.
  9. 22. Two nonadjacent angles are formed by two intersecting lines. The two angles are opposite rays, they are congruent.
  10. 24. If 3 sides of a triangle are congruent to 3 sides of a second triangle then the triangles are congruent. No angles are needed for this congruence postulate.
  11. 25. Coplanar lines that do not intersect. Any two vertical lines or horizontal lines.
Down
  1. 1. The distance around a 2-dimensional shape. The formula to find a rectangle is length+length+width+width.
  2. 2. The set of all points collinear to two points. It has one dimension.
  3. 3. Two coplanar angles with a common side or vertex but no common interior points. The two angles are side by side.
  4. 4. An angle whose measure is greater than 90 and less than 180. There is one type of this angle in an isosceles triangle.
  5. 5. Distance around a circle. It is the circle's perimeter.
  6. 6. The middle point of the line segment. Divides the segment into 2 congruent segments.
  7. 7. If 2 sides and the included angle of a triangle are congruent to 2 sides and the included angle of a second triangle then the triangles are congruent. The angle has to be in between the 2 sides in order for this congruence postulate to be true.
  8. 10. Amount of space that a 3D figure occupies. It uses cubic units.
  9. 11. If 2 angles and the non-included side of one triangle are congruent to two angles and the non-included side of a second triangle then the triangles are congruent. The 2 angles are next to each other, and the side is not between them, different from ASA.
  10. 14. The amount of space inside the perimeter of the flat object. To find this in a square, you do base times height.
  11. 15. A flat surface that forms the surface of a solid object. A cube has 6, a cylinder has 3, and a sphere has 1.
  12. 18. Sum of the areas of the lateral faces. This does not include the bases.
  13. 19. A solid geometric figure whose two end faces are equal and parallel. The sides are parallelograms.
  14. 21. If 2 angles and the included side of one triangle are congruent to two angles and the included side of a second triangle then the triangles are congruent. The side has to be in between the 2 congruent angles in order for the congruence postulate to be true.
  15. 23. Angles of equal measure. An example of vertical angles.