Geometry Vocabulary

4. triangle A triangle with all sides of different lengths.
6. reasoning Reasoning based on facts, definitions, and accepted properties.
10. A statement that combines a conditional statement and its converse.
12. Theorem In a right triangle, the square of the hypotenuse is equal to the sum of the squares of the other two sides.
13. Inequality Theorem The sum of the lengths of any two sides of a triangle is greater than the length of the third side.
14. polygon A polygon with all sides and angles equal.
16. A segment from a vertex to the midpoint of the opposite side.
17. A perpendicular segment from a vertex to the line containing the opposite side.
19. A quadrilateral with opposite sides parallel.
22. A six-sided polygon.
23. Formed by two rays with a common endpoint.

1. statement A statement in the form "If P, then Q".
2. A statement believed to be true based on observations.
3. triangle A triangle with all three sides of equal length.
5. points Points that lie on the same straight line.
7. points Points that lie on the same plane.
8. triangle A triangle with at least two sides of equal length.
9. A five-sided polygon.
11. Figures or shapes that are the same size and shape.
15. An example that disproves a conjecture.
18. Interior Angle Sum Theorem The sum of the interior angles of an n-sided polygon is (n-2)×180 degrees.
20. angles Two angles that share a common side and vertex but do not overlap.
21. A ten-sided polygon.