Applied Geometry Lesson 1 4 Conditional Statements Their

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Applied Geometry Lesson 1 -4 Conditional Statements & Their Converses Objective: Learn to write

Applied Geometry Lesson 1 -4 Conditional Statements & Their Converses Objective: Learn to write statements in if-then form and write the converses of the statements.

Conditional Statements Conditional statement: l A statement written in the form ifthen If-then statement:

Conditional Statements Conditional statement: l A statement written in the form ifthen If-then statement: l A statement written in the form ifthen

Definitions Hypothesis: l The part following the if in a conditional statement. Conclusion: l

Definitions Hypothesis: l The part following the if in a conditional statement. Conclusion: l The part following then in a conditional statement.

Identify the Hypothesis and Conclusion If it is Saturday, then Elisa plays soccer. H

Identify the Hypothesis and Conclusion If it is Saturday, then Elisa plays soccer. H C H: it is Saturday C: Elisa plays soccer If two lines intersect, then their intersection is a point. H: two lines intersect C: their intersection is a point

True or False If it is the fourth of July, then it is a

True or False If it is the fourth of July, then it is a holiday. True If an animal lives in the water, then it is a fish. False, counterexample whales are not fish

Conditional Statements 3 ways of writing If, then l If you are a member

Conditional Statements 3 ways of writing If, then l If you are a member of Congress, then you are a U. S. citizen. (then), if l You are a U. S. citizen, if you are a member of Congress. Everyday l All members of Congress are U. S.

Write 2 other forms of the statement. If points are collinear, then they lie

Write 2 other forms of the statement. If points are collinear, then they lie on the same line First identify the form of the original statement. The form is in if, then form So the forms we need are (then), if and everyday. Points lie on the same line, if they are collinear. (switch the subject since you can’t start a sentence with ‘they’. ) Points that lie on the same line are collinear.

Write 2 other forms If three points are noncollinear, then they determine a plane.

Write 2 other forms If three points are noncollinear, then they determine a plane. Three points determine a plane, if they are noncollinear. Three noncollinear points determine a plane.

Write 2 other forms All collinear points lie on the same line. If points

Write 2 other forms All collinear points lie on the same line. If points are collinear, then they lie on the same line. Points lie on the same line, if they are collinear.

Write 2 other forms If two lines are parallel, then they never intersect. Lines

Write 2 other forms If two lines are parallel, then they never intersect. Lines never intersect, if they are parallel. All parallel lines never intersect.

Converse The converse of a conditional statement is formed by exchanging the hypothesis and

Converse The converse of a conditional statement is formed by exchanging the hypothesis and the conclusion in the conditional. Not (then), if form!!!

Write the converse of the statement If a figure is a triangle, then it

Write the converse of the statement If a figure is a triangle, then it has three angles. As is: H: a figure is a triangle C: it has three angles. Converse: H: a figure has three angles C: it is a triangle. If a figure has three angles, then it is a triangle.

Write the Converse If you are at least 16 years old, then you can

Write the Converse If you are at least 16 years old, then you can get a driver’s license. If you can get a driver’s license, then you are at least 16 years old.

Write the Converse All collinear points lie on the same line. Need to write

Write the Converse All collinear points lie on the same line. Need to write it in if, then form first then change to converse. If points are collinear, then they lie on the same line. If points lie on the same line, then they are collinear.

True or False? If a figure is a square, then it has four sides.

True or False? If a figure is a square, then it has four sides. True Is the converse true? Converse: If a figure has four sides, then it is a square. False, counterexample would be a rectangle.

Homework Pg. 26 1 – 9 all, 10 – 36 E

Homework Pg. 26 1 – 9 all, 10 – 36 E