Geometry
Notes – Lesson 2.3
Name _________________________________________
Deductive Reasoning:______________________________________________________________________________________
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Law of Detachment: ______________________________________________________________________________________
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Ex 1: If a car’s battery is dead, then it will not start.
A mechanic works on a car and finds that its battery is dead. What can we conclude?
Ex 2: If a baseball pitcher pitches a full game, then he should not pitch the following day.
A baseball player pitches a complete game on Monday. What can we conclude about Tuesday’s game?
If it is snowing, then is the temperature is 32 o or lower.
It is 20o. Can I conclude that it is snowing?
Law of Syllogism: _______________________________________________________________________________________
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Ex 1: If Megan eats candy, then she will choose purple candy.
If candy is purple, then it is grape flavored candy.
Conclude: If Megan eats candy, then
.
Ex 2: If a figure is a square, then it is a rectangle.
If a figure is a rectangle, then it is a parallelogram.
Conclude: If a figure is a square, then
.
Ex 3: If a number ends in 6, then it is divisible by 2.
If a number ends in 4, then it is divisible by 2.
Conclude: ________________________________________________________________________________________________.
Ex: Use the Law of Detachment and the Law of Syllogism to draw conclusions…
If you live in Fort Collins, then you live in Larimer County.
If you live in Larimer County, then you live in Northern Colorado.
Annie lives in Fort Collins.
From Law of Syllogism:______________________________________________________________________
From Law of Detachment:____________________________________________________________________