Type of Class: Honors Geometry

Related VA SOL: G.1a and b

Time Frame: 90-minute block period

Objectives:

  • Students will be able to recognize an implication or a conditional statement.
  • Students will know how to negate a true statement.
  • Students will be able to identify and write the converse, inverse and contrapositive of the original statement.
  • Students will be able to translate the implication into symbolic form.

 

Materials:

  • Projector
  • Colored chalk
  • Paper and pencil
  • Markers/colored pencils
  • Worksheet
     

Procedures:

    1. Introduce an implication statement which is in the form “If … , then...”
    2. Show the symbolic representation of an implication statement. (p®q)
    3. Give two written examples of an implication statement. With the colored chalk, underline the hypothesis and the conclusion.
    4. Ask students to give additional examples and underline the hypothesis and the conclusion on the board.
    5. Vote on one implication statement that students want to work with. This will be the original statement.
      1. Write the converse of the original statement. (q®p)
      2. Introduce negation. Write the inverse of the original statement. (~p®~q)
      3. Write the contrapositive of the original statement. (~q®~p)
    6. Hand out the logical worksheet.
    7. Arts and craft: Ask students to create an implication statement and write the converse, inverse, and the contrapositive. They will decorate it with colored markers and pencils.
    8. Create hands-on activities such as cutting out the conditional statement and have students come up with the inverse, converse, and contrapositive. 

Assessment :
Students will write the converse, inverse and the contrapositive of the original statement for homework. The test should consist of conditional statements where students will be asked to write the converse, inverse and the contrapositive.

Suggestions/Comments :
For Standard Geometry students, when introducing the converse, inverse, and contrapositive, the teacher should give more than one example.