3rd grade g

1. Geometry vocabulary

2. Line segment A part of a line. It has 2 endpoints. ._____________.

3. line A straight path that goes on forever in both directions. It has no beginning. It has no end. -------------------

4. ray Part of a line It has an endpoint (starting point) It goes on in one direction forever. .-------------------

5. angle 2 rays with a common endpoint There are 3 types of angles Right angles: have a square corner Acute angle: is smaller than a right angle Obtuse angle: is larger than a right angle

6. Plane Figures Are flat figures (shapes) They can be open Or closed

7. Polygon Poly=many Is a closed plane figure that has 3 or more sides. The sides are line segments Triangle (3 sides) Square (4 sides) Pentagon (5 sides)

8. Quadrilateral A polygon with 4 sides and 4 angles

9. Parallelogram A quadrilateral with 2 sets of parallel sides

10. Rectangle A quadrilateral with 2 sets of parallel sides AND 4 right angles

11. Square 4 equal sides 4 right angles 2 sets of parallel sides

12. rhombus 4 equal sides

13. Trapezoid A quadrilateral with 1 set of parallel sides

14. Parallel Parallel are always the same distance apart. If you extended forever, they’d never touch each other

15. Triangle A polygon with 3 sides and 3 angles (corners)

16. Equilateral Triangle All 3 sides are equal length All three angles are the same size

17. Isosceles Triangle 2 sides are equal in length 2 angles are equal

18. Right Triangle One angle is equal to 90 degrees 90 degrees = a right angle

19. Congruent Shapes that are the same size and shape. They may be flipped or turned.

20. Not congruent May be a similar shape or size, but not the same.