How do you find the circumference of a cirlcle?

Compare these two waves: the blue and orange waves have the same pitch, but the blue wave is louder. the blue and orange waves have the same volume, but the blue wave has a higher pitch. the orange wave has a higher pitch, but the blue wave is louder. the blue wave has a higher pitch, but the orange wave is louder.

Paul can type 60 words per minute and jennifer can type 80 words per minutes. how does paul's typing speed compare to jennifer's

Find the length of the normal and the angle it makes with the positive x-axis. (see pictured below)