Geometry Logic Vocabulary

Match the following:

• a statement that disproves a conjecture

• Deductive Reasoning

• uses specific observations and patterns to make conjectures and draw conclusions

• Counterexample

• a statement that has not yet been proven to be true (like a hypothesis or best guess)

• Conjecture

• uses facts and general principles to draw conclusions

• Inductive Reasoning

Is this an example of inductive or deductive reasoning?

Every dog I have ever met is friendly. Therefore, every dog is friendly.

• inductive

• deductive

Is this an example of inductive or deductive reasoning?

All mammals have backbones. Humans are mammals. Therefore, humans have backbones.

• inductive

• deductive

Is this an example of inductive or deductive reasoning?

All birds lay eggs. Pigeons are birds. Therefore, pigeons lay eggs.

• inductive

• deductive

What does the vertical angles theorem state?

• When the measure of 2 angles adds up to 180 degrees, those angles are called supplementary angles.

• When the sum of 2 angles is 90 degrees, those angles are complementary.

• When 2 straight lines intersect, they create vertical angles that are congruent.

• The sum of 2 adjacent angles is equal to the resulting larger angle.

Which angles are congruent?

Which angles are supplementary?

What is the converse of this conditional statement?

If you are over the age of 5, then you know how to tie your shoes.

• If you know how to tie your shoes, then you are over the age of 5.

• If you don't know how to tie your shoes, then you are not over the age of 5.

• If you aren't over the age of 5, then you don't know how to tie your shoes.

• All people over the age of 5 know how to tie their shoes.

What is the inverse of this conditional statement?

If you are over the age of 5, then you know how to tie your shoes.

• If you know how to tie your shoes, then you are over the age of 5.

• If you don't know how to tie your shoes, then you are not over the age of 5.

• If you aren't over the age of 5, then you don't know how to tie your shoes.

• All people over the age of 5 know how to tie their shoes.

What is the contrapositive of this conditional statement?

If you are over the age of 5, then you know how to tie your shoes.

• If you know how to tie your shoes, then you are over the age of 5.

• If you don't know how to tie your shoes, then you are not over the age of 5.

• If you aren't over the age of 5, then you don't know how to tie your shoes.

• All people over the age of 5 know how to tie their shoes.