Deductive reasoning is a type of reasoning which goes from general to specific. Deductive reasoning is based on premises and if the premises are true, then the reasoning will be valid.

- In mathematics, If A = B and B = C, then A = C.
- Since all humans are mortal, and I am a human, then I am mortal.
- All dolphins are mammals, all mammals have kidneys; therefore all dolphins have kidneys.
- Since all squares are rectangles, and all rectangles have four sides, so all squares have four sides.
- If Dennis misses work and at work there is a party, then Dennis will miss the party.
- All numbers ending in 0 or 5 are divisible by 5. The number 35 ends with a 5, so it is divisible by 5.
- To earn a master's degree, a student must have 32 credits. Tim has 40 credits, so Tim will earn a master's degree.
- All birds have feathers and robins are birds, so robins have feathers.
- It is dangerous to drive on icy streets. The streets are icy now so it is dangerous to drive now.
- All cats have a keen sense of smell. Fluffy is a cat, so Fluffy has a keen sense of smell.
- Snakes are reptiles and reptiles are cold-blooded; therefore, snakes are cold-blooded.
- Cacti are plants and all plants perform photosynthesis; therefore, cacti perform photosynthesis.
- Red meat has iron in it and beef is red meat, so beef has iron in it.
- Acute angles are less than 90 degrees and this angle is 40 degrees so this angle is acute.
- All noble gases are stable and helium is a noble gas, so helium is stable.
- Magnolias are dicots and dicots have two embryonic leaves; therefore magnolias have two embryonic leaves.
- Elephants have cells in their bodies and all cells have DNA, so elephants have DNA.
- All cars have at least two doors and a Ford Focus is a car, so the Ford Focus has at least two doors.
- All horses have manes and the Arabian is a horse; therefore Arabians have manes.

Some deductive reasoning does not follow the classic reasoning pattern of A = B and B = C, then A = C. Some examples of other patterns are:

- Be careful around bees, they might sting you. (The reasoning is understood that all bees might sting.)
- It takes me an hour to get to the mall. If I leave at five o'clock I will reach the mall by six o'clock.
- That dog is growling so be careful or you might get bitten. (It is logical is the dog is angry, he might bite.)
- The apple hit me on the head because of gravity.
- There are three people in my family. Each one is tall, so everyone in my family is tall.

You can use deductive reasoning to better understand the world around you.

YourDictionary definition and usage example. Copyright © 2018 by LoveToKnow Corp

Link to this page

Cite this page

**MLA Style**

"Deductive Reasoning Examples." YourDictionary, n.d. Web. 18 November 2018. <https://examples.yourdictionary.com/deductive-reasoning-examples.html>.

**APA Style**

Deductive Reasoning Examples. (n.d.). Retrieved November 18th, 2018, from https://examples.yourdictionary.com/deductive-reasoning-examples.html