2.1 Conditional Statements

You like the ocean

You are a good swimmer

If you are a good swimmer, then you like the ocean.

You are not a good swimmer.

Andy goes to the emergency room

Andy breaks his arm

If an angle is obtuse then the angle measure is greater than 90° and less than 180°.

An angle is obtuse if and only if the angle measure is greater than 90° and less than 180°.

If an angle measure is greater than 90° and less than 180° , then the angle is obtuse.

An angle is not obtuse if and only if the angle measure is not greater than 90° and less than 180°.

The dog is black

The dog is not brown

The dog is not black

Some dogs are golden

If an animal is a puppy, then it is a dog.

If an animal is not a puppy, then it is not a dog.

If an animal is a dog, then it is a puppy.

If an animal is not a dog then it is not a puppy.

$$If\ x\ \ne5,\ then\ 3x\ \ne15.$$

$$If\ x\ =\ 5,\ then\ 2x\ =\ 10.$$  

$$If\ \ 3x\ \ne15,\ then\ x\ne5.$$

$$If\ x\ =\ 5,\ then\ 3x\ =\ 15.\$$  

$$If\ x\ \ne5,\ then\ 3x\ \ne15.$$

$$If\ x\ =\ 5,\ then\ 2x\ =\ 10.$$  

$$If\ \ 3x\ \ne15,\ then\ x\ne5.$$

$$If\ x\ =\ 5,\ then\ 3x\ =\ 15.\$$  

If an animal is a puppy, then it is a dog.

If an animal is not a puppy, then it is not a dog.

If an animal is a dog, then it is a puppy.

If an animal is not a dog then it is not a puppy.

If a figure is not a triangle, then the angles do not add to 180.

If the angles of a figure do not add to 180, then it is not a triangle.

If a figure has angles that add to 180, then it is a triangle.