Aruler is used for measuring the length of an object, and perimeter is the total length around the object. Given these facts, how would you measure the perimeter of the outside of an object?  among the following options:
- With a scale.
 - With a ruler.
 - With a thermometer.
 - With a hydrometer.
 - by indirect light
 - Under 32 degrees
 - focusing a lens
 - electron microscope


 

  With a ruler.       