What the the symbol for repeating decimal

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.

The value √10 and √15 are plotted on the number line

Iam a rectangle. my perimeter is 60 feet. how much are do i cover?