Geometry concepts

5. is a quadrilateral with exactly one pair of parallel sides.
6. is the amount of space a flat shape takes up on a plane.
10. a plane figure with seven straight sides and angles.
12. is a quadrilateral with opposite sides parallel.
13. a quadrilateral with two pairs of adjacent sides congruent and no opposite sides congruent.
17. is a trapezoid whose nonparallel opposite sides are congruent.
18. a parallelogram with four right angles.
19. a plane figure with nine straight sides and nine angles.
20. is the middle point of a line segment.

1. is a point that marks the end of a line segment or a ray.
2. is a polygon with three edges and three vertices.
3. is a special type of isosceles right triangle where the two legs are congruent to one another and the non-right angles are both equal to 45 degrees.
4. a plane figure with at least three straight sides and angles, and typically five or more.
7. a parallelogram with four congruent sides.
8. the sum of the squares on the legs of a right triangle is equal to the square on the hypotenuse.
9. a parallelogram with four right angles and four right congruent sides.
11. a plane figure with eight straight sides and eight angles.
14. a polygon with six sides.
15. a polygon with five sides and five angles.
16. a plane figure with ten straight sides and angle.