Find whether the following are sides of a right angled triangle

How many sides does a regular polygon have if each exterior angle measure is 45 degrees explain your answer, i really don't understand this.

Formulate alisha has a number in mind. if she adds three to her number the result is less than five. use this information to write and solve an inequality about alisha's number. then graph the solution set.

What is 100,000 times 1/100,000, using the standard method of multiplication? write the answer as 10 to a power.