geometry

2. straight line extending from the center of a circle or sphere to the circumference or surface.
3. triangle-A triangle which has two sides equal.
5. line segment between two points on a given curve.
8. parallelogram having four right angle
9. quadrilateral having both pairs of opposite sides parallel to each other.
12. triangle-A triangle having three unequal sides and angles.
13. closed plane curve consisting of all points at a given distance from a point within it called the center.
15. intersection point of two sides of a plane figure.
17. line segments-that cross each other.
18. polygon having six sides
19. continuous extent of length.
20. rectangle having all four sides of equal length.

1. polygon with four sides. note: squares, rectangles and trapezoids are also quadrilaterals.)
4. line segments-Line segments that do not intersect.
6. position in space.
7. angle-An angle less than 90 degrees but greater than 0 degrees.
9. line segments-Two line segments which cross to form 90 degree angles.
10. triangle-A triangle with one internal angle equal to 90 degrees.
11. triangle-A triangle with all sides equal and all angles equal.
14. segment-One part of a line.
16. polygon with 5 sides
21. angle-A 90 degree angle.