Conditional statement review quiz

The conditional statement: "If an angle is 80 degrees, then it is not a right angle". What is the inverse? Is the inverse true or false?

• If an angle is not 80 degrees, then it is a right angle.

  False

• If an angle is not a right angle, then it is 80 degrees.

  False

• If an angle is a right angle, then it's not 80 degrees.

  True

• An angle is 80 degrees if and only if it's not a right angle.

  True

The conditional statement: "If a pair of angles are supplementary, then they have a sum of 180 degrees".

What is the converse?

• If a pair of angles are not supplementary, then they do not have a sum of 180 degrees.

• If they have a sum of 180 degrees, then a pair of angles are supplementary.

• If they do not have a sum of 180 degrees, then a pair of angles are not supplementary.

• A pair of angles are supplementary if and only if they have a sum of 180 degrees.

Conditional: If I study, then I will not get a bad grade.

New statement: If I get a bad grade, then I did not study.

The new statement is the ____________ of the conditional.

• Converse

• Inverse

• Contrapositive

• Biconditional

The statement "If a number is divisible by 3, then it is odd" is false. Which of the following would be a good counterexample to prove this is false?

• 15

• 8

• 6

• This statement is true, so there is no counterexample needed.

Conditional: "If an angle is 60 degrees, then it is acute" is true. Give the truth value of the inverse of the statement. If false, also give a counterexample.

• True, no counterexample needed.

• False, counterexample is a 100 degree angle.

• False, counterexample is a 60 degree angle is obtuse.

• False, a counterexample is a 40 degree angle.