geooo quiz 2

  1. Conjecture
    Unproven statement that is based on observations
  2. Inductive reasoning
    use it when you find a patteren in specific cases and then write a conjucture for the general case
  3. counterexample 
    a specific case for which the conjecture is false
  4. conditional statement
  5. if then form
    The "if " part containts the hypothesis and the then part contains the conclusion
  6. Converse
    • If < A is obtuse then M< A =99
    • where you switch the two
    • exchange the hypothesis and conclusion
  7. Inverse 
    • Nagate both the Hypothesis and the conclusion
    • if m not equal to 99 theh <a is not obtuse 
    • make both negitive in the same order 
  8. contrapositive 
    • You first write the converse and then negate bothe the hypothesis and the conclusion
    • if <a ia not obtuse then M< A is not 99 
    • you switch them and make both negitive. 
  9. Perpendicular lines
    Two lines that intersect to from a right angle 
  10. equivalent statements
    When two statements are both true or both false. 
  11. Biconditional statement 
    A statement that contains the phrase "if and only if" 
  12. definition: If two lines intersect to form a right angle, then they are perpendicular lines
    • converse: if two lines are perpendicular, then they intersct to form a right angle
    • Biconditional: Two lines are perpendicular if and only if they intersect to from a right angle
  13. Deductive reasoning
    uses facts, definitions, accepted properties, and the laws of logic to form a logical argument. 
  14. Law of detachment 
    If the hypothesis of a true conditional statement is true, then the conclusion is also true. 
  15. Law of syllogism 
    • If Hypothesis p, then conclusion q
    • If Hypothesis q, then conclusion r. 
    • If hypotesis q then conclusion r. 

    if the top two are true then the bottom is also true
  16. Postulates or axioms
    rules that are accepted without proofs. 
  17. Theorems
    rules that are proved
  18. A Line perpendicular to a plane 
    If and only if the line intercects the plane in a point and is perpendicular to every line in the plane that interscts it at theat point. 
  19. Addition property 
    if a=b then a+c=b+c
  20. subtraction propertey 
    if a=b then a-c= b-c
  21. multiplication property 
    if a=b then ac=bc
  22. division propertey
    if a=b and c is not equal to 0 the a/c=b/c
  23. subsitution property 
    if a=b then a can be subsituted for b in any equation or expression
  24. proof
    logical argument that shows a statement is true
  25. two column proof
    has numbered statment and corresponding reason that show an argument in a logical orger
  26. theorem
    statement that can be proven
  27. congreence of segments
    • reflexive: for an seg. ab, ab is congrent to Ab
    • Symmetric: If seg AB is cong to CD then CD is cong to AB
    • Transitive: If seg AB is cong to CD and CD is cong to EF then seg AB is con to EF
  28. Right angle congruence theorem 
    all right angels are congrent 
  29. Congruent supplement theorem 
    • if two angle are supplementary to the same angle then they are congrent 
    •      If <4 and <5 are complemtrarty and <6 and <5 are complemtry then <4 is congrent to <6`
  30. Linear pair Postulate
    • If two angles for a liner pair, then they are supplementery 
    • <1 and <2 form a linear pair, so <1 and <2 are supplementary and M<1 + M<2 = 180
  31. Vertical angles congruence theorem 
    vertical angles are congruent 
Card Set
geooo quiz 2