- A dime is circle in shape
- Diameter is a measure of length through the center of a circle
- Hence, the diameter of a dime is a measure of length through the center of the dime

- The diameter of a dime is a measure of length through the center of the dime
- A ruler is a kind of tool for measuring length
- Therefore, a ruler can be used to measure the diameter of a dime

So, a ruler can be used to measure the diameter of a dime
Which tool is used to measure the diameter of a dime?
- A ruler is a kind of tool for measuring length 
- A dime is circle in shape 
- Diameter is a measure of length through the center of a circle