The perimeter of this shape is 120 π mm

What is the radius of the smaller semicircles?

Aline on the wall and a line on the floor are skew. always, sometimes, or never?

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.

1. how do you convert the repeating, nonterminating decimal 0. to a fraction? explain the process as you solve the problem.