1. Geometry in the Real World John Hoang Block 3 Theme: Sports

2. Point An undefined term in geometry, It defines a location and has no size.

3. Line (Segment) An undefined term in geometry , a line is a straight path that has no thickness and extends forever.

4. Plane An undefined term in geometry, it is a flat surface that has no thickness and extends forever.

5. Angle A figure formed by two rays with a common endpoint.

6. Perpendicular Lines Lines that intersect at 90° angles.

7. Parallel Lines Lines in the same plane that do not intersect.

8. Triangle A three-sided polygon.

9. Right Triangle A triangle with one right angle.

10. Pentagon A five-sided polygon.

11. Hexagon A six-sided polygon.

12. Square A quadrilateral with four congruent sides and four right angles.

13. Rectangle A quadrilateral with four right angles.

14. Trapezoid A quadrilateral with exactly one pair of parallel sides.

15. Parallelogram A quadrilateral with two pairs of parallel sides.

16. Circle The set of points in a plane that are a fixed distance from a given point called the center of the circle.

17. Cylinder A three-dimensional figure with two parallel congruent circular bases and a curved lateral surface that connects the bases.

18. Sphere A three-dimensional surface, all points of which are equidistant from a fixed point.

19. Rhombus A quadrilateral whose four sides all have the same length.

20. Oval An object having the general form or shape of an egg.

21. Star A figure usually having five or six points radiating from or disposed about a center.