A ruler is used for measuring the length of an object.
Perimeter is the total length around the object.
A ruler is used for measuring the perimeter of an object.
How would you measure the perimeter of the outside of an object? 

[A] With a scale.
[B] With a ruler.
[C] With a thermometer.
[D] With a hydrometer.
[E] by indirect light
[F] Under 32 degrees
[G] focusing a lens
[H] electron microscope